ROBERT COSTA: The impeachment debate heats up and the president tests his own party.

PRESIDENT DONALD TRUMP: (From video.)

From day one the wretched Washington swamp has been trying to nullify the results of a truly great and democratic election, the election of 2016.

They're trying; they're not getting very far.

ROBERT COSTA: President Trump remains defiant, but the impeachment debate takes sharp turns.

Close associates of his personal lawyer, Rudy Giuliani, are indicted, raising new questions about Mr. Trump's shadow foreign policy.

U.S. ATTORNEY GEOFFREY BERMAN: (From video.)

Parnas, on behalf of a Ukrainian government official, lobbied Congressman 1 to advocate for the removal of the then-U.S. ambassador to Ukraine.

ROBERT COSTA: And Turkish forces pound northern Syria after Mr. Trump's sudden decision to pull out U.S. troops.

Republican rifts emerge, next.

ANNOUNCER: This is Washington Week.

Once again, from Washington, moderator Robert Costa.

ROBERT COSTA: Good evening.

What began just weeks ago as an impeachment inquiry into President Trump's phone call with the Ukrainian president is quickly evolving into a full-fledged investigation of President Trump's use of power.

New congressional testimony this week painted a fuller picture for House Democrats of the president's shadow diplomacy, and on Friday Marie Yovanovitch, a 33-year veteran of the Foreign Service who was recalled as the U.S. ambassador to Ukraine in May, appeared on Capitol Hill at risk of losing her job.

She told House investigators that a State Department official told her that the president had long pushed for her ouster, even though the State Department did not have cause to remove her.

Ambassador Yovanovitch also warned Congress that personal and private agendas are now driving U.S. policy.

That was a nod toward Rudy Giuliani, the president's personal lawyer.

That testimony comes amid mounting questions about Giuliani and President Trump's role in his efforts abroad.

Two of Giuliani's business associates, Lev Parnas and Igor Fruman, were charged with campaign finance violations this week by federal prosecutors.

While the indictment did not accuse the president of wrongdoing, these two men were involved in Giuliani's campaign to pressure Ukraine to investigate the Biden family.

Amid this onslaught of developments, the White House is fighting back.

White House Counsel Pat Cipollone sent a letter to House Democrats this week saying the probe, quote, "violates fundamental fairness and constitutionally mandated due process" and said the White House would not comply with demands.

Joining me tonight, Margaret Brennan, moderator of Face the Nation and CBS News senior foreign affairs correspondent; Carl Hulse, chief Washington correspondent for The New York Times and author of Confirmation Bias; Toluse Olorunnipa, White House reporter for The Washington Post; and Abby Phillip, White House correspondent for CNN.

Margaret, when we look at this ambassador's testimony, Ambassador Yovanovitch, a 33-year veteran bringing her experience and expertise to Capitol Hill, how significant is it for her to say this president was operating outside of the chain of command with Rudy Giuliani?

MARGARET BRENNAN: Well, it was incredible testimony to read and it was incredibly moving for many of the State Department and national security officials who worked with her.

I mean, this was at least a three-time ambassador, 33 years of service as you said.

She served the country around the world.

And one of the most sort of moving parts of her testimony was saying, you know, at these moments you think because you have the American taxpayer's back and/or protecting U.S. interests and they're going to have yours, and instead she was personally attacked, removed from her job.

What she laid out in this testimony is exactly what you said, that it is not U.S. foreign policy that is being pushed in these shadow policies by Rudy Giuliani, the president's attorney; it is political interests.

And it is undermining, she argued, in that testimony to American democracy and our institutions.

So we have other diplomats we know who are poised to testify.

We also have Fiona Hill, former National Security Council official, who will be testifying on Monday.

And I'm told this is going to be that divide saying we had nothing to do with this, this is a project for the president that had nothing to do with American national security.

ROBERT COSTA: Toluse, why did people inside of the White House, inside the Cabinet, allow that project to happen, to allow the president to freelance with Rudy Giuliani?

What's going on inside?

TOLUSE OLORUNNIPA: Well, the president wanted to do it, so he did it.

The guardrails of the past with General Kelly and other people who could try to rein in the president, try to rein in some of his impulses, those are gone.

The president does what he wants.

Rudy Giuliani has a close relationship with the president.

He feels like - the president feels like there are only a certain amount of people that he can trust.

He doesn't feel like he can trust the people within the government.

He's talked about the deep state and people who are working against his interest, so he called his lawyer - his loyal, trusted lawyer who has been with him through all these various battles, including the Mueller investigation - and he said this is what I want to do, I want to go and investigate what happened in 2016 and this conspiracy theory that Ukraine was involved in election meddling, and I want to also get Ukraine to investigate Joe Biden and Hunter Biden and look into these allegations that have not been proven, that have actually been disproven in many cases.

ROBERT COSTA: So it just happens?

It just happens.

TOLUSE OLORUNNIPA: Yeah, the president wants to do it and he does it, and we see in these text messages from State Department officials that they try to figure out ways to contain the damage.

They try to figure out ways to make it not as bad as it would be if Rudy Giuliani didn't have any guidance, but now it's all sort of coming out into public view and it doesn't look very good.

ROBERT COSTA: Abby, the president says he can't trust the so-called deep state or bureaucrats he believes are aligned against him, yet he trusts Rudy Giuliani and Lev Parnas and Igor Fruman.

These are not Foreign Service officers who take that oath to the Constitution, to uphold the Constitution and represent U.S. interests.

Why this pull outside of the usual chain of command with these two men especially?

ABBY PHILLIP: Yeah, I mean, I think you hit it head on, the president still doesn't trust the very government that he runs right now.

He still believes that there is a deep layer or layer underneath the top layer of people who he can't trust - not just in the intelligence community, which he's been very vocal about, but also at the State Department and in other federal agencies - so he has leaned on Giuliani as someone who he knows personally and has known for a long time.

Now, this week he's claimed that he didn't know these two other gentlemen who were - who were charged this week, but he certainly was around them, and Giuliani was clearly working in concert with these two men to push a certain kind of agenda on the president.

One other piece of context in all of this, as Toluse alluded to, the guardrails are gone, and over the last year or so since the president has had an acting chief of staff, Mick Mulvaney, one of the things that White House sources talk about a lot is how Mulvaney really hasn't even bothered to try to contain the president.

Trump has never been a paragon of self-control, but other chiefs of staff have tried more to keep at least a handle on who he's talking to, when he's talking to them, and how the government is actually working at the president's direction.

He doesn't have a chief of staff who's doing that right now.

ROBERT COSTA: Carl, Abby says the guardrails are gone based on her reporting; so does Toluse.

There is still one guardrail in Washington; Congress has oversight of the executive.

If you're Speaker Pelosi, based on your reporting tonight, is she going to try to expand this impeachment probe beyond just the Ukrainian call and the Ukrainian matter?

She's hearing now from these top officials testifying.

We're going to hear from the EU ambassador, Gordon Sondland, next week.

How does she handle this new development?

CARL HULSE: I think that there is pressure on her to expand this beyond what's going on, and plus the Syria decision figures into that - I guess we're going to talk about that - but I still think she wants to keep this pretty narrowly focused.

They want to move quickly here.

They don't want to complicate things.

ROBERT COSTA: Why not?

CARL HULSE: Well, because they need to go faster.

The more you expand it, the more time is consumed.

I think talking virtually to everyone I've talked to on Capitol Hill this week while Congress is gone says they would like to see this concluded by the end of the year.

If you broaden it out too much it gets too big.

I think in some ways the Trump administration is making it easier for the Democrats if they're going to get into this position where they're just not going to cooperate at all.

And you know, everyone thought that letter was totally out of left field; there's no constitutional foundation there.

So that allows the Democrats to say, OK, we'll add that as an impeachment count; you're just obstructing.

ROBERT COSTA: So you think an obstruction charge could be added to the impeachment.

CARL HULSE: Yeah, oh, totally, and I think that that is what they're thinking.

They are just tired of the stonewalling.

ROBERT COSTA: Margaret, when you think about the foreign policy establishment inside the administration, the State Department, they have Secretary Pompeo there.

What's their view?

You've covered the State Department beyond all your great work abroad.

What's the mood inside of Foggy Bottom at the State Department as they deal with Secretary Pompeo and President Trump's conduct?

MARGARET BRENNAN: Well, you know, Secretary Pompeo likes to say he's bringing back swagger to the department, and I think the only swagger you heard people really saying they saw was the ambassador walking into Congress today to deliver that testimony.

A subpoena had to be delivered to put her in a position where she could appear because she is required, as a Foreign Service officer, to not just serve the oath that she made to the Constitution, but to abide by, in regulation, a subpoena delivered by Congress.

Her words in that testimony really described, as she said herself, a hollowed-out-from-within department, and I think that's the bigger-picture worry that I hear, not just from diplomats in this country but from around the world - our European partners who say who do I talk to, who is the professional, and where is the institution?

ROBERT COSTA: Who do they talk to, Margaret?

Who are they turning to?

Rudy Giuliani?

MARGARET BRENNAN: And this is exactly where it all comes together, is these individuals who are being empowered to carry messages for the president, to deliver conversations - whatever the, you know, aim is, if it's political measures or not - are not taxpayer-funded people who have taken an oath to the Constitution who are trained - four years - as Foreign Service officers are in how to conduct diplomacy, how to speak the language, and how to go through proper channels.

Those guard rails are often dismissed by the Trump administration as, oh, it slows things down, but those things are there because they are meant to also protect - processes meant to also protect the end goal, to get you to the foreign policy end game.

ROBERT COSTA: Toluse, it's important to note that, as much as there is real concern inside the administration from officials like the ambassador, you have the president as provocative and populist as ever on the campaign trail this week.

Here are some moments from a rally in Minnesota Thursday.

PRESIDENT DONALD TRUMP: (From video.)

The Democrats' brazen attempt to overthrow our government will produce a backlash at the ballot box the likes of which they have never, ever seen before in the history of this country.

(Cheers, applause.)

So in a desperate attempt to attack our movement, Nancy and Chuck - two beauties - have given control of the Democrat Party entirely over to the radical left, including Minnesota's own Representative Ilhan Omar.

The do-nothing Democrat extremists have gone so far left that they believe it should not be a crime to cross our border illegally, and it should be a crime to have a totally appropriate, casual, beautiful, accurate phone call with a foreign leader.

I don't think so.

ROBERT COSTA: Toluse, does that capture this White House's strategy or not?

TOLUSE OLORUNNIPA: That's completely their strategy going into this.

It's a base-focused, base-first strategy.

They are catering directly to the president's base by saying the Democrats want to overthrow what happened in 2016.

The Democrats want to perform a coup - very stringent language by the president of the United States trying to paint his opponents as not only, you know, opposed to him, but actually unpatriotic, as trying to subvert his government, and I think that is part of why he is trying to make himself a victim because he does believe that rallies his troops.

It gets people excited within the base of his party.

The polling that we've seen is showing that it's not really helping among independents.

It's showing that people are starting to move away from the president.

We have a majority of people supporting impeachment in a number of different polls, but he has made his choice that he is going to focus on his base all the way through 2020.

ROBERT COSTA: Abby, you have to wonder, do Republicans go along at this crossroads - at this impeachment crossroads.

Legislators are on recess getting confronted by constituents and reporters.

Republican Senator Cory Gardner of Colorado, in a tough 2020 race, faced questions this week about President Trump's pressuring of foreign nations.

QUESTION: (From video.)

Is it appropriate for a president to be - SENATOR CORY GARDNER (R-CO): (From video.)

Look, I think we are going to have an investigation - QUESTION: (From video.)

- to ask a foreign government to investigate - SENATOR CORY GARDNER (R-CO): (From video.)

- and it's a nonpartisan investigation.

QUESTION: (From video.)

But Senator, it's a yes or no question.

SENATOR CORY GARDNER (R-CO): (From video.)

It's a nonpartisan investigation.

It's an answer that you will get from a very serious investigation.

QUESTION: (From video.)

But would you be OK with it if it was a Democrat asking a foreign government for help?

SENATOR CORY GARDNER (R-CO): (From video.)

Look, here's what we're doing.

What we saw immediately was a jump to a very partisan - very partisan, serious use of a tool in the Constitution.

This is about an investigation that's taking place in the Senate Intelligence Committee.

That's where it should be.

What we've seen from the House of Representatives and Nancy Pelosi is a very partisan - partisanized effort.

ROBERT COSTA: When you are walking around the Senate hallways, Senator Gardner is usually one of the happiest characters on Capitol Hill - pretty grim scene for him as he faces reelection.

What does it tell you about the Republican Party - how he is handling those kind of questions?

ABBY PHILLIP: You can see the stress on his face because it's a hard argument to make.

He is basically making a process case that this is just unfair to the president, that we need to move slower, that we need to have a different process to evaluate this.

But he knows - just like a lot of other Republicans know - the facts are not on their side in this case.

President Trump's argument to his base that it was a beautiful, perfect, very cordial, appropriate call is not backed up by the transcript that he released.

I do think in this case, unlike the Mueller investigation, it's very easy to wrap your arms around what happened here.

That's one of the reasons why Nancy Pelosi has been so eager to just keep it simple; because the facts, as simple as they are, are not great for the president.

And I think that's one of the reasons you've seen the polls move.

It's also another reason why privately Republicans are very, very nervous about where this is all heading and how long they can continue to do what Cory Gardner just did.

CARL HULSE: Well, welcome to the next year of Cory Gardner's life.

ABBY PHILLIP: Yeah.

CARL HULSE: Right?

That was just a pretty good example of it - going to have a very hard time with this.

And in some ways, to me, the argument is tougher for these Senate Republicans who are in tough races, right, because they are - the people they are needing to appeal to are independents - especially in Colorado, Arizona - and it's going to be hard for them.

And now there is this specter of these criminal indictments over it, and people don't really know what's going on or understand campaign election law, but all of a sudden there's people that are being held on bond.

And I think people are starting to go, well, the White House is trying to brazen this out, and now it looks pretty serious.

ROBERT COSTA: When you say people, where is Chairman Richard Burr of North Carolina from the Senate Intelligence Committee?

Where is retiring Senator Lamar Alexander of Tennessee, based on your reporting?

CARL HULSE: Well, they've been on recess.

(Laughter.)

ROBERT COSTA: And they've been pretty quiet, but where are they - where are they really, Carl?

CARL HULSE: I think that - I think they are still not there.

I don't think they are there.

I think what you are going to hear from a lot of Senate Republicans, like Lamar Alexander - who people are looking to to say, well, he's not running again.

Maybe he's a person who can do it.

I think they are going to say this was inappropriate but it's not impeachable; the Democrats are rushing ahead here.

I think that is going to be the line.

But as more and more things come out, these kind of - you know, I've been here for an impeachment before and, you know, things kind of roll out and tend to take on a life of their own.

MARGARET BRENNAN: And I think it's interesting to see these talking points.

That's not just a Cory Gardner story; you're going to hear the same talking points - ROBERT COSTA: You've confronted that on Face the Nation again and again.

MARGARET BRENNAN: On live television, speaking over the person asking the question as Cory Gardner just did there because if you hear the case made, then you have to maybe address the point of the question instead of just framing this all as partisan, which allows you to sort of tune out the substance of what is being described.

And so there's not actually a conversation about what the president has done or said, and as you heard the president, even this week, he confirmed he actually does want China to investigate even though the Republican talking point had been it was a joke.

ROBERT COSTA: As Republicans consider their next steps on impeachment, they are being far more vocal on another front.

President Trump announced this week a U.S. troop withdrawal from northern Syria, marking a major shift in American foreign policy.

And days later, Turkey launched a military operation in the area targeting the U.S. ally in the fight against ISIS - the Kurds.

Turkish President Erdogan had long threatened to send troops over the border to create a buffer zone near the Turkish-Syrian border.

Many Republicans, however, were outraged by the president's move and spoke out about what they called a betrayal of the Kurds.

As I reported this week with the Post's Phil Rucker, that group included many Evangelical Christian leaders who are critical to the president's political base.

Senator Lindsey Graham of South Carolina, one of the president's top allies, introduced a bipartisan resolution this week that would put sanctions on Turkey, and tweeted Friday, "Every concern I had about President Trump's Syria decision is coming true in spades.

The reemergence of ISIS is on the way, and if you think only Europe is threatened, you are sadly mistaken."

Even as the president stood by his decision, his administration has not embraced Turkey's aggression.

Here's what Defense Secretary Mark Esper said Friday.

SECRETARY OF DEFENSE MARK ESPER: (From video.)

We oppose and are greatly disappointed by Turkey's decision to launch a unilateral military incursion into northern Syria.

This operation puts our SDF partners in harm's way.

It risks the security of ISIS prison camps and will further destabilize the region.

ROBERT COSTA: The president also said sanctions are on the table pending how this situation unfolds.

Toluse, the president didn't consult with U.S. allies, didn't consult with many people within his own government.

Why did he make this decision?

TOLUSE OLORUNNIPA: Well, if you listen to the president, he says he wants to end these endless wars; that it has always been his political instinct to get out of the Middle East.

He believes that going in was a big mistake, and we've spent a bunch of money since we've been there.

But why he did it the way he did it, it's in part because of what we said earlier.

There aren't the guardrails that you would originally have in a White House with a chief of staff working through the interagency process.

The president is operating on his own.

He gets on the phone with the leader of Turkey; he makes a compelling case, apparently, to the president; and the president says we're pulling troops out and we'll let the chips fall where they may.

And now we're seeing the administration scramble to try to come up with a policy based on that.

ROBERT COSTA: And the - and the Kurds are scrambling.

MARGARET BRENNAN: Yes, our allies on the battlefield who the U.S. had been advising and assisting and co-locating with, and continue to be.

There are still a thousand U.S. troops in Syria; they just moved back 20 to 30 kilometers from the Turkey-Syria border.

So when the president said yesterday there are no troops in Syria, that's not accurate as we learned today with these three artillery shells that hit very close to a U.S. outpost because Turkey was trying to target the Kurds, our allies there.

This is a bigger symbol and it is now a theme of abandoning allies, and so the abandonment of the Kurds in terms of pulling back was seen as a green light.

Now, I'm told President Trump really believes that he made the right call here, and you will have the Pentagon say we didn't abandon the Kurds; we've been working the phones, we're trying to broker something.

But the reality is Turkey is carrying this out because U.S. troops moved back - they moved back to avoid fire.

There were only, as Pompeo said today, about 60 guys or so on the ground.

That's not going to stop a Turkish invasion, but the U.S. Air Force would, and the U.S. Air Force was controlling that airspace.

The U.S. stopped, and so that is allowing in this incursion.

And as Toluse just rightly said, there's a retrofitting of policy to now match what the president agreed to on that call, which was simply he couldn't get Erdogan to back down and it backfired.

ABBY PHILLIP: And what he tweeted.

It's very hard for the administration right now to back off of this because the president himself tweeted that he basically gave Erdogan permission to go forward with this.

So at the White House today you saw the treasury secretary coming out and saying, well, we have the ability to punish Turkey in the future, possibly, if we ever decide to do that, but we're not going to do that right now.

It's something of an empty threat because it does nothing to resolve the situation on the ground, and it actually in some ways might even kind of make it more difficult for people to take the White House seriously when they say don't do this or else.

They basically disarmed themselves today in the press conference this morning when they announced that they had the tools to do this but they weren't going to use them.

CARL HULSE: What dissonance to hear the defense secretary say we're against this.

That's a policy that the president approved and caused.

It's just a very big disconnect here that I think people are struggling with.

MARGARET BRENNAN: Right, and the national community - national security community would argue, OK, if your end goal is pulling back out, let's negotiate how that happens, when it happens, in a way to continue to protect interests.

And when you take troops out, you give up leverage.

ROBERT COSTA: And what does that mean for Syria and Russia?

MARGARET BRENNAN: Well, it's a huge gain.

That's exactly the right question.

I mean, who wins on the battlefield?

This is now - there are Russian influences there, Iranian influences there, and it is only to the benefit when there is a vacuum because the Kurdish forces are no longer focusing their guns on ISIS fighters; they're trying to defend their own lives.

TOLUSE OLORUNNIPA: And that's one of the reason(s) Republicans have been so vocal in speaking out against this.

They do believe that Russia will benefit.

They do believe that Iran will benefit.

They do believe that this will end up being against the U.S. interest, in part because the president made a decision in a very abrupt way, in a way that seemed like he hadn't gone through the interagency process, hadn't heard from advisors.

And you are seeing Republicans break from him in a way that we don't normally see.

They're usually afraid to declare independence from this president, but in this case we have seen a lot of Republicans breaking from him, and I think that's part of the reason why things look so chaotic at the White House.

ROBERT COSTA: Does that tell you, Toluse, that his relationship with the GOP is maybe a little bit more fragile than we see on the surface, if they're speaking out so much on a policy issue but they're still speaking out - Evangelical Christians, Republican hawks?

Is his coalition at risk?

TOLUSE OLORUNNIPA: I think there is a lot of exhaustion with this president, that these Republicans as we saw with Cory Gardner, have to spend so much time explaining what the president is doing, twisting themselves into knots in order to defend him on a number of different issues.

So on this very clear policy objection that they have, it was very easy for them to speak out.

I do think the president still has a very strong stranglehold on the party, in part because all of these Republican lawmakers need his primary voters.

They're afraid of being primaried.

They're afraid of the base.

So on impeachment they're not - ROBERT COSTA: Do they actually take - do they actually take action, Carl?

CARL HULSE: Well, I think there will be action in Congress.

There's going to be very bipartisan action in the - in the House, in the Senate.

I mean, they want to respond to this.

And I think to your question there, though, it's like, are they going to be willing to man the barricades on impeachment to the same degree?

I mean, we saw an Illinois congressman this week say - ROBERT COSTA: John Shimkus.

CARL HULSE: - yeah - take me off the list of people who support Trump.

Now, that's just one person, but do you really want to go as hard as you might have wanted to go?

And they're very - they're really - they think they know more about this than the president does.

ROBERT COSTA: What are your Republican sources telling you, Abby?

Does this move on Syria make them a little bit unsettled, less willing to go to the barricades as Carl said?

ABBY PHILLIP: It feels like on foreign policy - and Syria's not the only place where this has happened - Republicans have been willing to push back on the president.

They did it when the president delayed imposing Russian sanctions.

They've done it repeatedly on foreign policy because I think they believe that this is where their base is willing to let them break with him on some issues.

ROBERT COSTA: Thanks for sharing your Friday night with us here on Washington Week.

I appreciate it.

We're going to have to leave it there.

And our Washington Week Extra is coming up next on our website, Facebook, and YouTube.

We'll discuss the challenges facing Vice President Pence as impeachment and foreign policy debates heat up.

I'm Robert Costa.

Have a great weekend.