10 Texas counties to watch in the Cornyn-Paxton clash: From the Politics Desk

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Steve Kornacki lays out the key parts of Texas that will determine whether Sen. John Cornyn can survive his primary tonight. Plus, we have the latest on Republican redistricting setbacks in South Carolina and Alabama.

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10 counties to watch in Texas tonight

Analysis by Steve Kornacki

A victory by Sen. John Cornyn in today’s Republican primary runoff in Texas would represent a major upset. The limited available polling shows him running behind state Attorney General Ken Paxton , who received a potentially decisive boost when President Donald Trump endorsed him last week.

Cornyn’s hopes depend on a repeat of March’s preliminary round, when he unexpectedly finished in first place over Paxton, 42%-41%, despite trailing in most polls. A third Republican, Rep. Wesley Hunt , who represents a Houston-area district, finished third on the multicandidate ballot with 17%.

A key to Cornyn’s first-place finish was his relative strength in most of the state’s population centers. Consider the 10 top vote-producing counties in the preliminary round, which made up about 45% of all votes cast statewide. Cornyn won seven of them.

Cornyn’s showing in these counties netted out to a 34,883-vote edge over Paxton. In the state’s other 244 counties, Cornyn lost to Paxton by a total of 3,065 votes.

Cornyn posted his best numbers in Dallas County and in the Austin area in Travis and Williamson counties . These tend to be areas with above-average concentrations of wealth and college degrees. Cornyn also had strong showings in Fort Worth’s Tarrant County and San Antonio’s Bexar County . To have a chance in the runoff, Cornyn will need all of these places to deliver for him again.

The only major population center where Paxton ran up landslide margins was in Montgomery County , home of The Woodlands, an enormous planned community that is defined in part by its deeply conservative politics. Montgomery produced the largest vote plurality of any county in the country for Trump in the 2024 presidential election. Expect another massive Paxton win here tonight. Could it be big enough, and backed by high enough turnout, to wipe out those Cornyn advantages elsewhere?

Texas Senate runoff will be a huge test of Trump's endorsements

More competitive in the preliminary March primary were Collin and Denton counties , each situated on the northern edge of the Dallas-Fort Worth metroplex. Both are experiencing rapid growth. They loom as swing areas tonight. So do Harris County , home of Houston and where about 10% of all votes will be cast, and its fast-growing suburbs in Fort Bend County . Cornyn and Paxton ran about evenly in these counties in March. Notably, Harris is the home base of Hunt, who also endorsed Paxton last week.

To have a chance tonight, Cornyn will want essentially a repeat of the first round of voting in these 10 counties. If he can do that, then he would need to hold his own in the rest of the state. This was the other key ingredient for him in the initial primary. While Paxton won more votes than him in rural and small-town Texas, the floor didn’t fall out for Cornyn. But can he show the same kind of resilience in these places now that Trump has come out against him?

🎥 Tune in to the Kornacki Cam when the first polls close in Texas at 8 p.m. ET to watch Steve break down the results.

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South Carolina’s Trump-backed redistricting push fails in the state Senate amid GOP opposition

By Jane C. Timm and Matt Dixon

The Republican-led South Carolina Senate voted against advancing a new congressional map, ending the redistricting effort in the state for now.

The failed vote was a surprise rejection of President Donald Trump , who had urged lawmakers to pass a redrawn map that eliminated the state’s single majority-Black district, represented by longtime Democratic Rep. James Clyburn .

The South Carolina House approved the map last week in hopes of putting it into place for this year’s midterm elections. As part of the effort, lawmakers also sought to set another primary election for the affected districts in August. But after early voting began Tuesday for the previously scheduled June 9 primary, some Republicans in the state Senate changed their tune, arguing it was too late to enact new district lines.

“Neither my conscience nor my common sense will allow me to stop an election that is already underway,” said state Sen. Richard Cash , a Republican who changed his vote because of the timing.

Advisers close to the White House — which has pressed Republicans across the country to pass new maps over the past year to shore up the party’s narrow House majority — said they were caught off guard by the failed vote in the South Carolina Senate, with one calling it a “betrayal.”

“We knew it was bumpy all along, never a guarantee,” one adviser told NBC News. “But the votes were there on the last vote and nothing changed.”

The adviser also said that the White House was not given a heads-up about the vote from South Carolina Republican Gov. Henry McMaster , which they would have expected if votes were changing. By Jane C. Timm and Matt Dixon

All members of the state Senate are up for re-election in 2028.

“These next two years are going to bring hell from the MAGA grassroots wing of the party already skeptical of many of these old guard GOP senators,” one longtime South Carolina Republican operative said.

🗺️ Related: A panel of federal judges blocked Alabama from using a Republican-drawn congressional map , saying it “intentionally discriminated based on race.” State Attorney General Steve Marshall said he would appeal the decision to the U.S. Supreme Court.

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That’s all From the Politics Desk for now. Today’s newsletter was compiled by Adam Wollner.

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