President Trump may have the will to reshape the Supreme Court for a generation, but a growing rift inside his own party threatens to deny him the Senate votes to do it. A Newsweek analysis found that Trump's aggressive campaign to unseat Republican senators who have crossed him has fractured the GOP caucus at precisely the moment he needs it united.
The math is unforgiving. Republicans hold 53 Senate seats. With every Democrat expected to oppose any Trump nominee, the president can lose no more than three Republican votes and still confirm a justice through Vice President JD Vance's tiebreaker. Right now, at least three GOP senators, Susan Collins of Maine, Lisa Murkowski of Alaska, and Thom Tillis of North Carolina, have shown little appetite for loyalty on judicial matters. A fourth defection would sink any nomination outright.
That is the backdrop against which Trump has chosen to wage primary wars against members of his own conference, a strategy that may feel satisfying but carries a steep institutional cost.
The most visible crack opened on May 16, when Louisiana Sen. Bill Cassidy lost his primary to Julia Letlow, the Trump-backed challenger. Cassidy had voted to convict Trump in the second impeachment trial, opposed several administration priorities, and recently announced opposition to White House ballroom funding in the budget reconciliation bill. Trump wanted him gone, and voters obliged.
Ten days later, on May 26, Texas held a Republican primary runoff pitting Trump-endorsed Ken Paxton, the state attorney general, against longtime Sen. John Cornyn, until recently the chairman of the Senate Judiciary Committee, the very body that vets Supreme Court nominees.
Collins, the Maine Republican, did not hide her displeasure. She told Newsweek she found the Paxton endorsement baffling.
"I don't understand. He [Paxton] is an ethically challenged individual. John Cornyn is an outstanding senator and merited the president's support."
That kind of public rebuke from a sitting senator signals more than a policy disagreement. It signals a willingness to break ranks when the stakes are highest, including on a Supreme Court vote.
Collins is running for reelection in a state that has trended Democratic, where Trump's net approval sits at minus-17. Murkowski defeated a Trump-backed challenger in 2022 and has shown no inclination to fall in line since. Tillis announced this year he will not seek reelection in 2026, freeing him from any political pressure the White House might apply. All three voted together to force Senate debate on Trump's Iran war powers. Tillis has also opposed several administration judicial nominees.
These are not fringe members of the caucus. They are veteran legislators with committee influence, and each has demonstrated a pattern of independence on judicial confirmations specifically.
Neither Justice Clarence Thomas nor Justice Samuel Alito has signaled an intention to step down. Thomas has told associates he "continues to love the work." Alito hired law clerks for the next term, has a book scheduled for publication in October, one day after the new term begins, and has publicly stated his plan to remain on the bench. Both justices, however, are among the oldest members of the Court, and the question of succession looms over every term.
Trump told Fox Business in April that he was "prepared" to nominate two or three justices if vacancies arise. He has mentioned Sen. Ted Cruz and Judge Aileen Cannon as possible nominees. The ambition is there. The votes may not be.
Thomas, who has served on the Court since 1991, has faced ugly personal attacks from political opponents throughout his tenure. His willingness to remain in the job despite that hostility is consistent with the determination associates describe.
Alito's March hospitalization for dehydration raised brief health concerns, but the law-clerk hiring and book plans suggest a justice settling in, not stepping aside. If either man did retire, the window to confirm a replacement would be narrow, and narrowing.
Republican strategist Mike Madrid laid out the broader danger in blunt terms:
"A year ago, nobody ever believed that the Democrats would be within striking distance of getting a majority in the Senate. And now it's, you know, it's a coin toss. It's as likely as that it's not. That jeopardizes the entire Trump agenda. And of course, Supreme Court justice becomes a big part of that consideration."
Democrats need four seats to take control. A year ago, that seemed far-fetched. Today, with Trump's approval underwater in key battleground states, minus-14 in Michigan, minus-3 in Texas despite winning the state by 14 points in 2024, the midterm landscape has shifted. Matt Klink, president of Klink Campaigns, warned that falling presidential approval could drag down the entire Republican ticket.
"The danger for Republicans is that Trump's approval becomes the emotional shortcut voters use to make decisions in races they otherwise haven't fully engaged."
If Democrats flip the Senate in the 2026 midterms, and new members take office in January 2027, any Supreme Court vacancy after that point becomes functionally unfillable for Trump. The confirmation window, in other words, runs roughly through the end of next year. That is not a long time in Supreme Court terms.
The Court is already navigating several consequential cases with direct implications for Trump-era policy. A vacancy fight layered on top of those rulings would intensify an already volatile political environment.
Jim Kessler of Third Way, the centrist think tank, argued that Trump's endorsement strategy has created a self-inflicted problem. The senators Trump has targeted are either leaving politics or newly liberated from party discipline.
"Revenge is a two-way street. All the politicians that he's gone after are either finished with their career or they hope to have a second start by being someone who took Trump on. So somebody like John Cornyn [of Texas], who's been a Republican loyalist his entire life and was stabbed in the back by Trump."
Kessler also assessed the specific confirmation math:
"People like Lisa Murkowski and Susan Collins were already gonna be a no on any Supreme Court justice because Collins is up for reelection and Murkowski will be up soon. And then you've got Tom Tillis as well. So, you know, I don't think the votes are there for that."
One can dispute the source, Third Way is a center-left outfit with every incentive to talk up Republican dysfunction. But the underlying vote count is not a matter of spin. It is arithmetic. Three firm defections plus one wobbly senator equals a failed nomination.
Trump has publicly clashed with Supreme Court justices he himself appointed, a reminder that his relationship with the judiciary is transactional even when it comes to allies. The willingness to burn bridges extends in every direction.
Cornyn's situation is instructive. He chaired the Judiciary Committee, the gatekeeper for every federal judge, and was, by any measure, a reliable conservative vote. Trump endorsed Paxton over him anyway, reportedly calling Paxton "a sleazebag, a terrible guy, who is bad for Louisiana", an apparent geographic mix-up, since Paxton is from Texas. The insult and the endorsement sat side by side, a snapshot of a strategy driven more by personal grievance than institutional logic.
The likeliest near-term scenario is that neither Thomas nor Alito retires. Both have said as much. But "likeliest" is not "certain," and health, age, and personal circumstance can change the calculus overnight. If a vacancy does open, the confirmation fight will test whether Trump's primary campaigns have purchased loyalty or manufactured opposition.
Thomas, at 76, has remained a towering originalist voice on the Court, recently calling for the dismantling of race-based redistricting in a Louisiana ruling. His jurisprudence has shaped a generation of conservative legal thought. Replacing him with another originalist would preserve the Court's current balance. Failing to replace him, because the votes weren't there, would be a generational loss for the right.
The same is true for Alito, whose opinions on religious liberty and executive power have anchored the Court's conservative wing. A vacancy left unfilled, or filled by a compromise nominee weakened to secure moderate Republican votes, would amount to a retreat.
And that is the tension Trump's strategy has created. The president has every right to support the candidates he prefers. Primary elections are how parties settle internal disagreements. But governing requires coalition management, and coalition management requires the occasional swallowed grievance. The Senate is not a loyalty test. It is a vote-counting exercise.
The attacks on figures like Thomas from media personalities and Democratic politicians make it all the more important that Republicans present a unified front when it matters most. The left would like nothing more than to see a conservative Court seat go unfilled because Republicans couldn't stop fighting each other.
Accountability in the Senate is a good thing. So is winning. The question is whether the president's endorsement strategy has made the second harder in pursuit of the first, and whether, when the moment comes, the Republican conference can count to fifty.
You can settle scores or you can seat justices. History suggests you rarely get to do both.