Margins matter for Cornyn in hotly contested primary

• That's true for the GOP establishment, which has already spent more than $50 million to bolster Cornyn.
• It's also the case for Trump, who has resisted numerous entreaties to endorse Cornyn, Paxton — the expected top two vote-getters — or Rep. Wesley Hunt (R-Texas).
• Trump likes to back winners — or at least candidates who show that they're in shot of winning.

The hope is that the race will reset if Hunt comes in a distant third, allowing Cornyn to pull ahead of Paxton and regain the momentum he lost when Hunt entered the race.

Zoom out: GOP operatives tell Axios' Alex Isenstadt they're worried that their worst possible scenario is unfolding in both of Texas' Senate primaries: A victory by state Rep. James Talarico on the Democratic side, followed by a clear win for Paxton.

• Republicans widely believe Talarico and his "progressive Christian" campaign pitch would be a tougher general election opponent than Rep. Jasmine Crockett, a liberal who's drawn national attention for her sharp criticism of the Trump administration.

At the same time, GOP strategists say Paxton— a MAGA loyalist they regard as a weaker November candidate than Cornyn — has the advantage over the incumbent on Tuesday, if recent polls are right.

• "A Paxton versus Talarico match in November would be unnecessarily competitive and costly" for Republicans while facing tight races nationwide that could cost them control of the House and Senate, one GOP operative told Axios.

The other side: Some GOP strategists think placement matters more than margin. They can't envision Trump endorsing a second-place finisher under any circumstances.