AMNA NAWAZ: President Trump has successfully ousted a Republican senator who voted to convict him in his impeachment trial five years ago.

After losing his bid for a third term, Louisiana's Bill Cassidy took a thinly veiled swipe at the president last night.

SEN.

BILL CASSIDY (R-LA): Sometimes, it doesn't turn out the way you wanted to, but you don't pout, you don't whine, you don't claim that election was stolen.

You thank the voters for the privilege of representing the state or the country for as long as you have had that privilege.

AMNA NAWAZ: It's another sign of Trump's grip on the party, even as his popularity sinks to all-time lows.

Here to unpack this weekend's results in Louisiana and the next big test in Kentucky tomorrow, it's our Politics Monday duo, Amy Walter of The Cook Political Report With Amy Walter and Tamara Keith of NPR.

It's great to see you both.

AMY WALTER, The Cook Political Report: Hello.

TAMARA KEITH: Good to be here.

AMNA NAWAZ: As you well know, Bill Cassidy, yes, voted to convict President Trump in 2021.

Also, he was the deciding favorable vote for Pete Hegseth's confirmation, for RFK Jr.

And, Amy, as you know, he didn't just lose.

He finished third behind the Trump-backed candidate -- that's Representative Julia Letlow -- and State Treasurer John Fleming, who now go to a run-off.

What's the lesson here?

AMY WALTER: Yes, well, I think there are three ways to get elected right now as a Republican, to win a Republican primary.

Either get endorsed by Donald Trump, don't run against someone who has been endorsed by Donald Trump, and don't vote to impeach him.

There's been one person, one senator, who has been able to go the opposite of all three of those and still survive.

And that's Lisa Murkowski, the senator from Alaska.

She's able to win -- she was able to win reelection in 2022 because of the way that they vote in Alaska.

It's an all-party primary, so Democrats and independents can vote for her.

When Cassidy made that vote, by the way, in 2021, Louisiana had that same system, a very similar system.

The governor, Republican governor of the state, scrapped that system.

And so for the first time, he now had to run with just Republicans.

But I'm glad you put that clip on, Amna, about what he said at his concession speech, because I think that's the more interesting thing looking forward.

He clearly has nothing left to lose, but he's in Washington until January.

So does he use this time, where -- as he chastised the president for saying, you can't just do these things because you're unhappy that somebody stood up for the Constitution, is he going to follow through now and maybe become a real pain for the administration, maybe deny certain people from getting a nomination to a Senate-confirmed slot?

AMNA NAWAZ: Say the things he wasn't willing to say before, in other words.

AMY WALTER: Correct.

AMNA NAWAZ: What about you, Tam?

TAMARA KEITH: Yes, and Senator Thom Tillis of North Carolina is another person who, it's like, are retired, they can say whatever they think finally.

TAMARA KEITH: And you have already seen Cassidy, not just in that speech, but in just the last several hours, speaking out against policies from the Trump administration he doesn't support.

So I think that you're seeing that already.

In terms of the president's power within the party, he is proving that, in Republican primaries, his power is still mighty.

And what that means is that he is able to exact revenge against people who stand up to him.

You saw that in those Indiana state Senate primaries that I covered, where five out of the seven challengers won.

You also saw that in Louisiana.

And Trump's team is pretty confident that you're going to see that again in the Massie race in Kentucky.

We will wait for those results, obviously.

But this is about power.

Even though, as you said, President Trump's approval rating is in a really bad place, and he is starting to see some creep with some Republicans starting to separate from him a little bit, that is, in polls, he is able to maintain his power by proving that he can punish people who cross him.

And so, while he still has the House and the Senate, he is able to get them to do what he wants and not really push back on the things that a robust balance of power would call for.

AMNA NAWAZ: So let's bring folks up to speed on what we could expect to see in Kentucky, because tomorrow is the culmination of the most expensive House primary ever.

The incumbent, as you mentioned, Thomas Massie, is in a dead heat with former Navy SEAL Ed Gallrein.

Massie, just as a reminder for folks, voted against the so-called One Big Beautiful Bill.

He said it was concerned about how much it added to the debt.

He also pushed for the release of the Epstein files.

And we heard President Trump today talk about that race and weigh in.

Take a listen.

DONALD TRUMP, President of the United States: Massie's the worst congressman in the history of our country, always voting against Republicans and good values.

So get rid of Thomas Massie.

AMNA NAWAZ: Amy, is he going to have the same influence in Kentucky?

AMY WALTER: Yes, so here's the real question for voters in this district.

Remember, Thomas Massie's been in Congress since 2012, so he's not brand-new.

This is not new the way he -- voting against the Republican leadership in the House is something he's done consistently.

So, are voters here going to feel that the bigger issue is he was disloyal to Trump?

Or will they look at him and say, but actually he was loyal to this sort of - - his sort of iconoclastic brand, which is, he feels very strongly about certain things and he votes that way, and voters in the state will reward him for standing up on those values, many of them driven on issues like the deficit?

He's libertarian on some other issues.

AMNA NAWAZ: Yes.

AMY WALTER: But I think you're right.

I think it was the Epstein issue itself that became the real flash point.

AMNA NAWAZ: Tam, what do you think?

TAMARA KEITH: Yes.

And this is a Republican primary in a red state.

So it is a pretty small electorate that's going to show up for a Republican primary in a red state, even though so much money has been spent on it.

But that message from President Trump really just clearly shows how much this matters to him politically to be able to vanquish anyone who dares to cross him.

He also has now gone after Congresswoman Lauren Boebert, who campaigned with Massie.

She also supported the Epstein legislation.

AMNA NAWAZ: I want to ask you both too about a story we reported on earlier about the DOJ creating this $1.8 billion fund that could compensate allies of President Trump who claimed they were targeted by previous administrations.

And that was all part of the president dropping his lawsuit against the IRS for releasing - - leaking of his confidential tax returns.

This is a lot of money, Amy, billions of dollars we're talking about, on top of another billion dollars we talk about for security for the White House ballroom.

How does that line up with how American voters are looking at this?

AMY WALTER: Right.

Well, they're not feeling very great about the economy or the president's handling of it.

The New York Times -- I just had to write down what this was, the New York Times poll out this weekend.

Voters' perception of how Trump's handling the economy, 28 percent approval rating on handling the -- I'm sorry -- the cost of living.

And so this is not an issue in which the president is looking particularly strong.

But, fundamentally, I think the issue for voters right now, what's really driving this, is Iran.

And while the ballroom and the DOJ fund certainly do not help make the case or help Republicans make the case that they care about the cost of living, the biggest impediment right now to making things affordable is the Strait of Hormuz being closed.

And while that is still closed, it's going to be very hard really for anybody to feel confident about the economy going forward.

TAMARA KEITH: Yes, and there is a straight line from the way President Trump campaigned in 2024 to this settlement.

He said, I am your retribution.

He has spent -- he has focused on other things, but one consistent through line in his entire first year-and-a-half is seeking retribution against those who he believes have wronged him.

And he feels that the Biden Justice Department was weaponized against him and his supporters.

And so this settlement fund -- although President Trump is claiming he doesn't know anything about it and he's hearing it's well-received, this settlement fund is part of a broader effort from President Trump to rewrite history about that era from 2021 through him winning reelection again.

And in some ways, this was baked in the cake when he won.

AMNA NAWAZ: Tamara Keith, Amy Walter, thank you so much.

TAMARA KEITH: You're welcome.

AMY WALTER: You're welcome.