The Texas primary runoff has become one of the most closely watched political contests of the year, and for good reason. It pits four-term Senator John Cornyn against Texas Attorney General Ken Paxton in a fight that could redefine the Republican Party’s direction heading into the 2026 midterms. With President Donald Trump throwing his weight behind Paxton, the race has turned into something bigger than just a Senate primary, it’s now a litmus test for Trump’s continued grip on the GOP.

A Battle Brewing in the Lone Star State

Senate Republicans are preparing for what could be one of the costliest general elections in Texas history. The state’s controversial attorney general appears poised to dethrone Cornyn, a fixture in Texas politics for decades. Recent public polling shows Paxton leading heading into Tuesday’s runoff, despite a long list of scandals trailing him.

Cornyn’s Senate colleagues have rallied behind him, arguing he stands a far better chance against Democratic nominee and state Representative James Talarico in a general election. Paxton, meanwhile, comes with significant baggage, including allegations of corruption, financial misconduct, and personal infidelity.

The Money Problem Facing Paxton

Fundraising tells a striking story in this race. Talarico, the Democratic challenger, pulled in over 27 million dollars in just the first three months of the year, an amount that outpaces what many Senate candidates raise across entire campaigns. Cornyn has also leveraged decades of donor relationships to bring in serious cash.

Paxton, on the other hand, has lagged considerably. He reported just over 7 million dollars in fundraising and roughly 2 million in his campaign account at the start of May. The Lone Star Liberty PAC, his biggest supporting super PAC, had around 1.9 million on hand.

Cornyn warned supporters at a Houston event that propping up Paxton’s general election bid could drain hundreds of millions from other competitive Senate races, and even then, victory wouldn’t be guaranteed.

Why This Race Matters Nationally

Republicans are working to protect their slim 53 to 47 Senate majority. The party already faces tough defensive battles in Maine, Ohio, and North Carolina, while also eyeing flips in Georgia and Michigan. Senate Majority Leader John Thune acknowledged the challenge, noting that Republicans must defend 24 seats compared to just 9 for Democrats.

Texas, despite leaning red, isn’t cheap. With over 31 million residents spread across nearly 270,000 square miles, plus expensive media markets in Houston and Dallas-Fort Worth, statewide campaigns routinely cost a fortune. The 2024 Cruz versus Allred race drew over 210 million dollars in ad spending alone.

Trump’s Endorsement Changes Everything

For months, Senate Republicans and even members of Trump’s own political team lobbied hard for the president to back Cornyn. That effort fell flat when Trump officially endorsed Paxton last week.

Representative Lance Gooden, a Paxton supporter, didn’t mince words, calling Trump’s endorsement “the kiss of death” for Cornyn’s campaign. The endorsement injected fresh momentum into Paxton’s run, especially among the hard-right base that typically dominates runoff turnout.

Cornyn’s Legacy and Establishment Backing

Cornyn isn’t going down without a fight. He has never lost an election in Texas and was instrumental in shifting the state firmly into Republican territory back in the 1990s. He was the first Republican elected as Texas Attorney General since Reconstruction and turned the office into a launching pad for conservative policy nationwide.

He also served as the Senate’s second-highest ranking Republican from 2013 to 2019 under Mitch McConnell, and made his own bid for majority leader in 2024. That track record has earned him support from heavyweight Texas Republicans like former Governor Rick Perry, former Senator Phil Gramm, and Ross Perot Jr.

Key fundraising highlights for Cornyn include:

• Over 17 million dollars spent by Perry’s Lone Star Freedom Project super PAC
• More than 10 million dollars from One Nation, a GOP leadership-aligned group
• Over 414 million dollars raised for fellow Republicans during his career

Matt Mackowiak, Cornyn’s spokesperson, questioned whether those donors would stick around if Paxton becomes the nominee, saying long-built relationships can’t simply be handed off.

Democrats See an Opening

Democrats are openly hoping for a Paxton win, believing his scandal-ridden record gives them their best shot at flipping the Texas Senate seat. Madison Andrus, a spokesperson for the Democratic Congressional Campaign Committee, suggested that nominating Paxton would only worsen Republicans’ problems with voters already frustrated by rising costs.

Cornyn himself has warned that a Paxton nomination could become an “albatross” for Republicans running in other Texas races, including House contests.

Record-Breaking Spending and Other Key Races

This Senate primary has already smashed records, becoming the most expensive in American history. Cornyn and his allies have shelled out more than 90 million dollars heading into Tuesday, according to AdImpact data.

The runoff also features another fierce contest, with Representative Chip Roy and state Senator Mayes Middleton battling to replace Paxton as attorney general. Both candidates are working hard to out-conservative each other in a race that has grown increasingly hostile.

What Happens Next?

The Senate Republicans’ campaign arm has been vocal in its criticism of Paxton, with communications director Joanna Rodriguez once describing his behavior as “truly repulsive and disgusting.” Whether the group would back Paxton in a general election remains unclear. The Senate Leadership Fund, tied to Republican leadership, stayed out of the primary entirely.

Gooden argued that Republicans must rally behind Paxton if he wins, warning that failure to do so would shake confidence in the party’s commitment to conservative values. Cornyn, for his part, has pledged to “support the ticket” in November regardless of who emerges victorious.

As Tuesday approaches, the Texas primary runoff stands as more than just a state contest. It is a defining moment that could reshape the Republican Party’s identity and reveal just how deep Trump’s influence still runs.