Cornyn and Paxton Face Off in Final Day of Texas Republican Senate Primary Runoff
TL;DR
Texas Republicans vote on May 26 in a runoff between incumbent Senator John Cornyn and Attorney General Ken Paxton for the GOP Senate nomination — a contest that has consumed $135 million in total spending and fractured the state party. Trump's late endorsement of Paxton, combined with polling showing either nominee in a near-tie with Democrat James Talarico, has raised the prospect that a safe Republican seat could become competitive in November for the first time since 1988.
Texas Republicans go to the polls on May 26 to settle what has become the costliest and most consequential intra-party fight in U.S. Senate history. Incumbent Senator John Cornyn, who has held his seat since 2002, faces Attorney General Ken Paxton in a Republican primary runoff that has consumed roughly $135 million in combined advertising, drawn a presidential endorsement with one week left on the clock, and forced both candidates into a scorched-earth messaging campaign that may leave the eventual nominee damaged heading into November .
The race is a stress test for two competing theories of Republican politics in the Trump era: whether institutional seniority and legislative experience still matter in a party that increasingly rewards loyalty to a single leader, or whether the MAGA movement's gravitational pull is now strong enough to topple a four-term senator in the second-largest state in the country.
How We Got Here: The March Primary
Cornyn and Paxton emerged from a three-way March 3 primary in which neither cleared the 50% threshold needed to avoid a runoff. Cornyn led with 42.0% to Paxton's 40.5%, with U.S. Representative Wesley Hunt collecting 13.5% . That razor-thin 1.5-point margin — just over 30,000 votes — set up the May 26 runoff.
The March primary drew approximately 1.3 million Republican voters . By contrast, the runoff's early voting period produced roughly 820,000 Republican ballots cast by mail and in person, representing about 4.4% of registered voters . That retention rate — roughly 63% of primary early voters returning for the runoff — is high by historical Texas runoff standards, reflecting the intensity of the contest.
The Money Race: A Record-Breaking Imbalance
The financial disparity between the two campaigns has been staggering. In first-quarter 2026 filings, Cornyn raised approximately $9 million across all his committees and held $8.2 million in cash on hand. Paxton raised $2.2 million and held $2.6 million . The gap widened further when super PAC money entered the picture: the pro-Cornyn Texans for a Conservative Majority raised $9.5 million in Q1, compared to $2.1 million for the pro-Paxton outside group .
In the March primary, pro-Cornyn forces spent roughly $69 million on advertising — approximately 17 times the $4 million spent by Paxton and his allies . The runoff narrowed that ratio to about four-to-one, with $19.9 million in pro-Cornyn ad spending versus $5.1 million for the Paxton side through mid-May .
Houston businessman John Nau has been identified as a central figure in the pro-Cornyn outside money operation, contributing millions to the super PAC backing the incumbent . Senate Republican leadership, including Majority Leader John Thune, has also invested heavily in protecting Cornyn's seat .
Despite being massively outspent, Paxton has remained competitive — a fact that underscores the limits of money in a race where Trump's brand carries independent weight.
Trump's 11th-Hour Endorsement
The race's decisive moment may have arrived on May 19, when President Trump endorsed Paxton with one week of voting remaining . Trump had remained neutral through the March primary, telling supporters he "liked all three candidates." After the runoff was set, he promised to endorse "soon" — then waited more than two months .
Trump's endorsement statement called Paxton "a true MAGA Warrior who has ALWAYS delivered for Texas" and cited two specific policy positions: Paxton's support for eliminating the Senate filibuster and passing the SAVE Act, a voter eligibility verification measure . Trump also noted that Cornyn "was not supportive of me when times were tough" — a reference to Cornyn's criticism of Trump ahead of the 2024 presidential campaign .
The endorsement triggered an immediate cascade. Wesley Hunt, whose 13.5% primary vote share represents the most sought-after bloc of persuadable Republican voters, endorsed Paxton the same day . The combined Trump-Hunt alignment gave Paxton what amounts to a unified MAGA front heading into election day.
Cornyn's response was measured. "I think that ship has probably sailed," the senator told reporters, adding that his campaign would maintain "a packed campaign schedule" across Texas metro areas .
The Conservative Credential Fight
Paxton's campaign has built its case against Cornyn around a handful of Senate votes that, in the attorney general's framing, reveal an insufficiently conservative record.
The most prominent target is the Bipartisan Safer Communities Act of 2022, the first major federal gun safety legislation in decades. Cornyn helped negotiate and shepherd the bill, which enhanced background checks for young gun buyers and provided funding for state crisis intervention programs. Paxton has repeatedly branded Cornyn an "anti-gun establishment politician" for his role in the law .
Beyond guns, Paxton has attacked Cornyn for supporting U.S. aid to Ukraine, for his past openness to the DREAM Act providing a path for some undocumented immigrants brought to the U.S. as children, and more broadly for a willingness to work with Democrats that Paxton characterizes as capitulation .
Cornyn's actual conservative ratings tell a more complicated story. His lifetime American Conservative Union score is 93% . Heritage Action for America, which grades on a stricter curve, has rated him as the ninth most conservative among Republican senators, at 86% in the current Congress . But that aggregate masks significant variation: Heritage scores for Cornyn have ranged from 35% in the 118th Congress to 96% in the 119th, reflecting specific votes that either aligned with or diverged from the conservative movement's priorities .
The National Journal ranked Cornyn the second most conservative senator based on his 2011-2012 voting record, with a 93.8% composite conservative score . By most quantitative measures, Cornyn is well to the right of the Senate median — but in a primary where the relevant comparison is not the Senate as a whole but the expectations of Texas Republican primary voters, those numbers have not insulated him from Paxton's attacks.
The Case for Cornyn: Seniority and Results
Cornyn's defenders argue that his two-plus decades in the Senate have produced concrete policy outcomes that a freshman senator — regardless of ideology — cannot replicate. He has chaired the National Republican Senatorial Committee twice, served on the Judiciary and Intelligence committees, and accumulated the kind of institutional relationships that translate into legislative influence .
Former U.S. Representative Ted Poe, backing Cornyn, has argued that "Texas benefits from the seniority Cornyn has accrued" and that the senator has been "a reliable partner in the upper chamber" . Senate Majority Leader Thune's endorsement carries the implicit message that Republican leadership views Cornyn as essential to its governing coalition .
The skeptic's counter is fair: what, specifically, has that seniority delivered? Cornyn's most visible bipartisan achievement — the gun safety bill — is the very legislation his opponent uses against him. His role in judicial confirmations and behind-the-scenes negotiations is real but harder to campaign on. The tension between legislative effectiveness and primary electability is the central paradox of Cornyn's candidacy.
The Case Against Paxton: Legal Baggage and General Election Risk
Paxton enters the runoff carrying legal and ethical liabilities that are unprecedented for a major-party Senate nominee in recent Texas history.
In 2015, a state grand jury indicted Paxton on two counts of securities fraud (first-degree felonies) and one count of failing to register with state securities regulators, stemming from accusations that he encouraged other legislators to invest in a McKinney-based company without disclosing that the firm was paying him to promote its stock . After years of delays, Paxton reached an 18-month pre-trial agreement under which prosecutors would drop the charges in exchange for full restitution to victims, 100 hours of community service, and 15 hours of legal ethics education .
In 2023, the Texas House impeached Paxton on articles alleging he gave preferential treatment to a donor, misapplied public resources, obstructed justice, and made false statements. The Texas Senate voted 16-14 to acquit him on all articles, ending his suspension from office . The acquittal did not resolve the underlying allegations — it merely meant the Senate declined to remove him.
Pro-Cornyn advertising has hammered these vulnerabilities relentlessly, with ads attacking Paxton as "incompetent, corrupt and adulterous" . The strategic calculation is straightforward: Cornyn's allies spent tens of millions of dollars airing allegations against Paxton that Democratic nominee James Talarico can repurpose at zero cost in the general election .
The General Election Shadow
Multiple polls show that either Republican nominee would face a competitive general election against Talarico — but Paxton's numbers are consistently weaker.
A Texas Southern University poll (April 22-May 6, 1,223 likely voters) found Cornyn leading Talarico 45%-44%, while Paxton and Talarico were tied at 45% each . A University of Texas/YouGov survey showed Talarico leading Paxton 42%-34% and leading Cornyn 40%-33% . Slingshot Strategies/Texas Public Opinion Research found Talarico ahead of Paxton 46%-41% and ahead of Cornyn 44%-41% .
Republican analyst Mark Jones warned that the primary has created "collateral damage," with the candidates having done "Democrats' dirty work" by damaging each other's images . Some Republican strategists have expressed concern that a Paxton nomination could produce the party's first statewide loss in Texas since 1994 . One poll suggested a Paxton nomination could drag down Republican margins by five to eight points in down-ballot races .
These numbers represent a remarkable situation for a state that has not elected a Democratic senator since 1988.
The counter-argument from Paxton supporters is that general election polls this far out are unreliable, that Texas's structural Republican advantage (Trump carried the state by roughly 14 points in 2024) provides a substantial buffer, and that Talarico — a Democratic state representative whom GOP operatives have already begun attacking as too liberal for Texas — would face his own vulnerabilities in a general election campaign .
Early Vote Geography: A Divided Map
The early voting data reveals a geographic split that mirrors the candidates' respective coalitions.
Cornyn's metro strongholds retained early voters at higher rates than Paxton's suburban and exurban bases. Travis County (Austin), where Cornyn won by 24 points in March, kept nearly 80% of its Republican early vote from the primary. Dallas County, where Cornyn won by 18 points, retained about 70% — 45,974 early votes in the runoff versus 64,948 in the primary .
Paxton-friendly counties showed lower retention but higher turnout rates among registered voters. Montgomery County, where Paxton won by 27 points in March, retained about 60% of its early vote but posted roughly 6% turnout among registered Republican voters — higher than the 3% rate in Cornyn-favoring metro counties .
The Cornyn campaign has explicitly sought high turnout, stating: "Unlike Ken Paxton, we want high turnout. We are working to turn out as many Republicans as possible" . The implication is that Paxton's path depends on a smaller, more ideologically motivated electorate — a common dynamic in runoff elections, where lower turnout historically favors the more insurgent candidate.
Total Republican runoff turnout is projected somewhere between 1 million and 1.25 million, with potential for up to 1.5 million if election day participation surges .
The March Geography and Trump's Map
Paxton's primary coalition tracked closely with Trump's strongest counties. In Texas counties where Trump won 80% or more of the 2024 vote, Paxton led Cornyn 45%-40% . In more moderate Trump counties (50-80%), Cornyn led by about one percentage point. In counties that Kamala Harris won, Cornyn led 44%-40% .
This geographic alignment is central to understanding Trump's endorsement. Paxton's voters are Trump's voters. The endorsement was not an ideological statement so much as a ratification of an existing coalition — one built on cultural conservatism, anti-establishment sentiment, and personal loyalty to the president.
What Happens Next
The runoff concludes a primary season that has cost the Republican Party of Texas both money and unity. State GOP Chair Abraham George called for an end to negative advertising before the runoff, a plea that went unheeded by both sides . Multiple Republican officials have publicly worried that the bruising contest will benefit Talarico regardless of which candidate prevails .
If Cornyn wins, he returns to Washington with diminished standing among the party's Trump-aligned base but with his institutional power intact and a relatively straightforward general election path.
If Paxton wins, he enters the general election as a first-time Senate candidate carrying the weight of a $135 million negative ad campaign — much of it funded by his own party — against a Democratic opponent in a state where general election polls already show a competitive race. The question of whether Texas's structural Republican lean can absorb those liabilities will be tested in November.
Only two incumbent U.S. senators from Texas have lost a primary in the last 100 years . Whether Cornyn becomes the third depends on whether Trump's endorsement and Paxton's MAGA coalition can overcome a four-to-one spending disadvantage and a decade of legal controversy — all in a single day of voting.
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Sources (21)
- [1]Cornyn and Paxton bury each other in negative ads as Senate GOP runoff enters final stretchtexastribune.org
The Texas Senate primary is the most expensive in U.S. history with more than $110 million in advertising. Pro-Cornyn forces outspent Paxton four to one in the runoff.
- [2]Inside the closing week of the Texas GOP Senate runofftexastribune.org
Both campaigns make closing arguments as a total of $135 million has been spent in the Texas Senate primary. Only two incumbent Texas senators have lost a primary in 100 years.
- [3]United States Senate election in Texas, 2026 (March 3 Republican primary)ballotpedia.org
Cornyn led Paxton 42.0%-40.5% in the March 3 primary, with Wesley Hunt at 13.5%. No candidate cleared 50%, triggering a runoff.
- [4]2026 Election: Early voting numbers provide insight ahead of Tuesday's runofffox7austin.com
About 820,000 Texans cast Republican ballots in early voting for the runoff, versus 1.3 million in the March primary.
- [5]Early voting in John Cornyn-Ken Paxton GOP Senate runoff reveals divided turnout maptylerpaper.com
Dallas County retained 70% of its March early vote while Cornyn-friendly Travis County kept 80%. Paxton counties like Montgomery retained about 60% but posted higher registered-voter turnout rates.
- [6]John Cornyn outraises Ken Paxton as Senate runoff loomstexastribune.org
Cornyn raised $9 million in Q1 2026 with $8.2 million cash on hand. Paxton raised $2.2 million with $2.6 million on hand. The pro-Cornyn super PAC raised $9.5 million.
- [7]The donors behind Cornyn and Paxton's Senate fighttexastribune.org
Houston businessman John Nau is a central figure in the pro-Cornyn outside money operation, contributing millions to the super PAC.
- [8]Trump endorses Ken Paxton over incumbent John Cornyn in Texas Senate primary runoffnpr.org
Trump endorsed Paxton one week before the runoff, calling him 'a true MAGA Warrior' and citing his support for eliminating the filibuster and passing the SAVE Act.
- [9]Trump delivers 11th-hour endorsement to Paxton in Texas Senate runoffaxios.com
Trump had remained neutral through the March primary before endorsing Paxton on May 19, one day after early voting began.
- [10]Trump endorses Ken Paxton over Sen. John Cornyn ahead of Texas Republican Senate runoffnbcnews.com
Trump cited Paxton's loyalty and said Cornyn 'was not supportive of me when times were tough.' Wesley Hunt endorsed Paxton the same day.
- [11]What to expect in the Texas US Senate Republican primary runoffpbs.org
In Trump 80%+ counties, Paxton led 45%-40%. In moderate Trump counties, Cornyn led by about 1 point. Only two incumbent Texas senators have lost a primary in 100 years.
- [12]Paxton, Cornyn head to Texas GOP runoff after Wesley Hunt finishes thirdfoxnews.com
Wesley Hunt finished third with 13.5% in the March primary and later endorsed Paxton on the same day as Trump's endorsement.
- [13]How John Cornyn's historic gun safety bill has become a reelection liabilitykrgv.com
Paxton has branded Cornyn an 'anti-gun establishment politician' for helping pass the Bipartisan Safer Communities Act of 2022.
- [14]Where Paxton and Cornyn stand on immigration, IVF and other issuestexastribune.org
Paxton has attacked Cornyn for supporting Ukraine aid, past openness to the DREAM Act, and his role in the bipartisan gun safety bill.
- [15]Sen. John Cornyn - Heritage Action Scorecardheritageaction.com
Cornyn's Heritage Action scores range from 35% (118th Congress) to 96% (119th Congress). His lifetime ACU score is 93%.
- [16]Texas Attorney General Ken Paxton makes deal to end securities fraud charges weeks before trialpbs.org
Paxton reached a pre-trial deal to resolve 2015 securities fraud indictment: restitution, 100 hours community service, 15 hours legal ethics education in exchange for charges being dropped.
- [17]Ken Paxton - Wikipediaen.wikipedia.org
Texas Senate voted 16-14 to acquit Paxton on all impeachment articles in September 2023, ending his suspension from office.
- [18]James Talarico's Chances Against John Cornyn vs. Ken Paxton a Week Before Texas Runoffnewsweek.com
TSU poll shows Cornyn-Talarico at 45-44 and Paxton-Talarico tied at 45-45. UT/YouGov shows Talarico leading both. Analyst warns of 'collateral damage' from primary.
- [19]Will the Texas primary run-off give Democrats a chance to flip the state?aljazeera.com
One poll suggested a Paxton nomination could lead to a 5-to-8-point decline for Republicans in down-ballot races.
- [20]A 'vegan' and 'Tala-freak-o': GOP prepares a furious general election messaging blitz against Talaricocnn.com
GOP operatives have already begun preparing attack lines against Democratic nominee James Talarico ahead of the general election.
- [21]Texas GOP chair calls for end to negative ads in Senate runofffox4news.com
Texas GOP Chair Abraham George called for an end to negative advertising in the Senate runoff, a plea unheeded by both campaigns.
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