GEOFF BENNETT: Early voting is under way in Texas, a key state this year in the battle for control of the U.S.

House and Senate.

One of the leading Democrats in the Senate primary in the state, State Rep.

James Talarico, announced that his campaign raised $2.5 million in the last day after late-night host Steven Colbert said CBS blocked him from airing an interview from Talarico on his broadcast, which was later shared on YouTube.

Talarico is one of a handful of Democrats running to flip the state's Senate seat blue this fall, as longtime Republican Senator John Cornyn faces a challenging primary to remain the Republican candidate on the ballot.

For more on the political battle gearing up in the Lone Star State, we're joined now by Ashley Lopez.

She covers politics for NPR.

Thanks for being here.

ASHLEY LOPEZ, Political Correspondent, NPR: Yes, thanks for having me.

GEOFF BENNETT: So, as we mentioned, James Talarico has raised millions in this race.

He's still facing this primary challenge from Democratic Congresswoman Jasmine Crockett.

How is this contest shaping up and what does it reveal about the direction of the Democratic Party in Texas?

ASHLEY LOPEZ: The race initially was not quite as contentious.

This wasn't -- these weren't two candidates who are very dissimilar.

There's not a lot to fight about sort of substantively.

But I think, as more money is pouring in, Democrats are looking at the Republican side, that primary, how that's shaping up.

And I think they smell some blood in the water.

And so there's a lot more attention.

It's getting more contentious.

And I mean, like I said, substantively speaking, these two candidates are pretty similar.

There's not a lot of big differences there.

But, stylistically, Congresswoman Jasmine Crockett is more of a fire brand.

She seems to be very willing to take on Republicans in Congress, at least rhetorically, in a way that other Democrats aren't.

And James Talarico, who's a Statehouse member in Texas, he is trying to strike a more kind of conciliatory tone.

And so it is going to be very interesting to see what Democratic voters sort of prefer here.

GEOFF BENNETT: Let's talk about the Republicans, because, as you said, Democrats smell blood in the water for Cornyn.

John Cornyn has represented Texas in the U.S.

Senate for some 20 years.

He's now facing a primary challenge.

How real is the threat to his political future?

ASHLEY LOPEZ: I mean, if we take polling seriously, it's a pretty serious concern for him.

And this is very rare.

I should say like, it's been 14 years since a U.S.

senator has lost their primary race.

This does not happen often.

Incumbency power is very powerful.

This doesn't happen all the time.

This is another case where the candidates substantively on policy are not very different.

Ken Paxton, the attorney general in Texas, would like to position Cornyn as less of a MAGA candidate.

But if you look at his voting record, Cornyn votes with the president quite a bit.

And I think that's something his campaign says too.

But Ken Paxton is a little more stylistically like the president.

He has had a lot of legal trouble at his time as the attorney general.

So I think there's a lot of similarities there.

But that creates a situation where, is he as good of a general election candidate come November, with all the legal baggage that Ken Paxton has had in the past 10 years?

Is that going to be a liability for him?

GEOFF BENNETT: And this is also the first election since Texas' mid-cycle redistricting.

So what effect is that going to have on the House races across the state?

ASHLEY LOPEZ: There's a lot of open questions.

I think they were drawn basically to create five more safe seats for Republicans.

But Republicans did that basically by looking at particularly Latino turnout, Latino voting.

Latino voters in nature are swing voters.

I think that that's a less of a good bet than Republicans would think from what I'm seeing right now.

So we will see.

It could be that Republicans gained those five seats or maybe four, but you have to remember Texas redistricting caused other states to redistrict like California.

And so that might be a wash anyway.

GEOFF BENNETT: Yes.

Well, another reason why we're focused on Texas is because this is the first major primary contest of the year in what is expected to be a volatile political cycle.

What early signals are you watching for?

ASHLEY LOPEZ: Texas is an interesting -- it's an interesting case because the candidates are so similar.

I don't think it's going to tell us substantively what policies, what messaging works.

But I think it will tell us how fired up Democratic voters are.

Primaries by nature motivate base voters.

And this is a part of the Democratic Party that is really upset right now.

Base voters are telling Democratic leaders they're unhappy with the people that they have in power.

They're unhappy with the way Democrats have been handling the second term of the Trump administration.

And so I'm going to be curious to hear what voters are telling lawmakers now and politicians through primary elections.

GEOFF BENNETT: Every cycle, it seems, the question is asked, is this the year that Texas turns blue?

I'm not going to ask you to speculate.

Based on your reporting, what are Democrats telling you?

ASHLEY LOPEZ: There's like this narrative that Democrats have in Texas, which is demographics are destiny there.

As the state becomes more ethnically and racially diverse, by sheer numbers, Democrats will do better.

And that has not panned out for many, many cycles.

Texas is a state with uniparty control for now 30 years-plus.

That is a hard hurdle to clear.

The big wild card in all of this is if John Cornyn loses his primary race, because incumbent power is very powerful in general elections for Senate races.

And if he loses that and there is not an incumbent running against a Democrat, this is a different dynamic than we have seen in Texas in a long time.

GEOFF BENNETT: Ashley Lopez, political correspondent for NPR, thanks for being here.

ASHLEY LOPEZ: Yes, thank you.