Texans go to the polls Tuesday in a Republican Senate runoff between four-term incumbent John Cornyn and Attorney General Ken Paxton that the paper has argued for two days will reshape the June 1 floor math on the Iran war-powers resolution [1]. The University of Houston Hobby School poll fielded April 28 to May 1 showed Paxton at 48% and Cornyn at 45%, with 7% undecided and a margin of error of 2.83 points [2]. RealClearPolitics has Paxton up 3.2 in the average. Polls close at 7 p.m. Central.

The paper's Monday feature on the T-minus-one count framed the race as the most consequential single-state war-authorization signal of the cycle. Last Thursday, the paper's earlier feature located Cornyn inside the small cohort of Republicans Senator Bill Cassidy has been talking to about a recess-period vote. A Cornyn defeat removes the most pro-Pentagon Texas Republican from the next floor vote and detaches one of the institutional senators Cassidy needs to hold the line.

Cornyn took 41.9% in the March 3 primary; Paxton took 40.7%; Congressman Wesley Hunt took less than 15% and was eliminated [3]. Senate Majority Leader John Thune endorsed Cornyn, citing what he calls the safer bet on a reliably red Texas seat. Turning Point Action, Representatives Lance Gooden and Troy Nehls, and a long roster of Trump-aligned activists endorsed Paxton. Governor Greg Abbott and Senator Ted Cruz declined to endorse — Cruz's neutrality, after his 2020 Cornyn endorsement, the most public sign of the runoff's volatility [3].

The Iran war-powers resolution advanced out of committee last week by a 9-7 margin, with three Republicans joining all six Democrats [4]. June 1 floor action requires 51 votes. Eight Republicans are listed by leadership as gettable; Cornyn is one of them. Paxton, asked by a Dallas Morning News reporter Friday whether he would have voted with Cassidy on the resolution, said he would not — that the Senate "should not be tying the president's hands while Iran is the threat it is." Paxton has not signed the discharge petition Cornyn signed on March 31 to bring the Hormuz monitoring bill to the floor.

The runoff dynamics favor Paxton on turnout, as Punchbowl News reported in March. Republican runoffs draw a base that overrepresents the activist primary electorate; Cornyn's general-election strength does not transfer. Texas's open-primary rules limit runoff participation to voters who either cast a March 3 Republican primary ballot or did not vote in either primary. Early voting from May 18 to 22 ran modestly ahead of the 2022 runoff turnout but well below 2014, when Cornyn last faced a primary challenge.

What the paper is watching Tuesday night is not just the result. It is whether Cassidy, who has stayed quiet since the Monday Memorial Day cycle, says anything Tuesday about the runoff's implications for the war-powers vote. Cassidy's office told the paper Monday afternoon it had "no comment for now." A Cornyn loss removes one of the eight gettable Republicans from the active count; a Cornyn win means he must signal his June 1 vote inside five days against a primary that ended with 45% of his own party voting to retire him.

The November race shifts coverage as well. Cornyn and Paxton both trailed Democratic nominee James Talarico in head-to-head polling fielded by Fox 7 Austin in April, with Cornyn's gap slightly smaller [2]. A Paxton win throws Texas onto the competitive Senate map for the first time since 2018. Cook Political and Sabato have rated the seat Likely Republican; both flagged a Paxton nomination as the scenario that could move it.

Two endorsements landed Monday night. Trump issued a fresh endorsement of Paxton on May 19 via Truth Social and reshared a March video of his Conroe rally Monday. Cornyn's super PAC, Texans for a Conservative Majority, dropped a final-hours ad in Houston, Dallas, and San Antonio markets focused on Paxton's 2023 impeachment by the Texas House and the Montblanc pen incident the Cornyn campaign has cited for two months [3]. Whether any of that moves a percentage point in a runoff is the smallest open question of the night. The largest is whether the man casting the vote that decides the Iran war-powers resolution is named John Cornyn or his successor.

-- SAMUEL CRANE, Washington