Donald Trump's power to reshape Republican politics faces a real test this Saturday in Louisiana, where Senator Bill Cassidy is fighting for his political life in a primary he was supposed to cruise through. The incumbent Republican, running for a third term in a state that leans heavily GOP, now stands in third place among likely voters, a dramatic reversal driven entirely by the president's personal vendetta.
Cassidy's sin was straightforward: he voted to impeach Trump after January 6, then doubled down by supporting an independent commission to investigate the Capitol assault. Even as secretary, Cassidy has criticized some of Kennedy's policies and opposed Trump's push to confirm wellness influencer Casey Means as surgeon general, leading the president to blame him for her withdrawal. That defiance sealed his fate.
In January, Trump summoned U.S. Representative Julia Letlow into the race with his endorsement in hand. She accepted immediately, along with state treasurer John Fleming, transforming what should have been a coronation into a brutal three-way fight. An Emerson College poll released last month showed Cassidy trailing both Letlow and Fleming, who are running virtually tied for the lead.
This is politics operating under Trump's new rules. Louisiana State University political scientist Robert Hogan described the president's abandonment of Cassidy as probably the "death knell" for his Senate career. The pattern is becoming clear: Republicans who cross Trump face extinction, not just criticism.
The senator tried to make peace with the president. After his impeachment vote poisoned relations, Cassidy made a calculated move by casting the deciding vote to advance Robert F. Kennedy Jr.'s nomination to lead the Department of Health and Human Services out of the Senate health committee he chairs. The decision contradicted his own medical credentials and stated support for vaccines, yet it failed to win Trump back.
A gastroenterologist who co-founded a clinic for uninsured patients in Baton Rouge, Cassidy moved to the Senate in 2014 after defeating Democratic Senator Mary Landrieu. During Trump's first term, he worked to repeal the Affordable Care Act. His relationship with the president collapsed entirely after the January 6 assault and his vote to convict at Trump's impeachment trial, though that effort fell short.
Louisiana's Republican Party censured Cassidy in 2021 for that conviction vote. When Trump returned to office last year, the senator's vulnerability grew acute.
The state's Republican primary system has also tilted against him. In 2024, Governor Jeff Landry, a Trump loyalist, worked with the legislature to change the rules so that candidates are nominated only by registered Republicans and unaffiliated voters, excluding others who might have been willing to cross party lines. Political strategist Ron Faucheux suspects the changes were designed specifically to eliminate options for Trump-defiant Republicans.
"The new primary system is geared to help staunch, conservative, pro-Trump candidates get elected," Faucheux said, noting that the structure pushes nominated Republicans into runoffs against Democrats that few think they can lose.
Cassidy's only realistic path forward is to finish in the top two on Saturday and advance to a June runoff, where unaffiliated voters whose views remain unpollled could potentially make a difference. But even reaching a second round would leave him facing a significant Trump headwind.
Both Letlow and Fleming are leaning hard into their Trump connections. Letlow touts endorsements from both the president and Governor Landry. Fleming's campaign circulates photos of him with Trump. Cassidy has countered by attacking Letlow directly, calling her "Lib Letlow" and highlighting her past support for diversity programs at the University of Louisiana at Monroe, statements she has since repudiated.
If Cassidy loses this weekend, he will join a growing roster of Republicans whose careers Trump has ended. Five of seven Republican Indiana state senators who opposed a Trump-backed gerrymandering effort lost their primaries earlier this month. In North Carolina, Thom Tillis decided to retire after breaking with Trump over his domestic policy priorities, leaving Republicans fighting to hold a Senate seat they expected to win.
Author James Rodriguez: "Cassidy's political death march is a masterclass in how completely Trump has rewritten the Republican primary playbook, turning personal loyalty into the only currency that matters."
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