Rep. Julia Letlow is advancing to a runoff in the Republican primary for Senate in Louisiana, as Sen. Bill Cassidy became the first incumbent elected U.S. Senator to lose renomination in 14 years. 

Letlow, who is endorsed by President Donald Trump, and Louisiana state Treasurer John Fleming will face off in a June 27 runoff. The Democratic nomination is also headed to a runoff between businessman Gary Crockett and Jamie Davis, a farmer and former state House candidate. The Republican candidate is overwhelmingly favored to win the general election in Louisiana, which Trump carried by 22 points in the 2024 presidential election. 

Letlow formally jumped in the race in January, a few days after Trump preemptively endorsed her to run for the seat in a January 17 post on Truth Social. He called her a “Great Star” and a “TOTAL WINNER,” writing “RUN, JULIA, RUN!!!”  

Letlow was first elected to Congress in a 2021 special election to replace her husband, Luke Letlow, who was elected to the seat in 2020 but died of COVID-19 before he could take office. Letlow, a former teacher, highlighted her role as a mother to two children and her support for Trump in her announcement video. 

“In a state as conservative as ours, we shouldn’t have to wonder how our senator will vote when the pressure’s on,” she said. “Louisiana deserves conservative champions — leaders who will not flinch.”

Cassidy, a gastroenterologist, has served in the U.S. Senate since 2015. In 2021, he was one of just seven Republican senators to vote to convict Trump in his impeachment trial for inciting the January 6, 2021, insurrection at the U.S. Capitol. 

Cassidy leads the Senate committee overseeing health care and voted to confirm Robert F. Kennedy as secretary of Health and Human Services (HHS) in Trump’s second term despite his concerns over Kennedy’s anti-vaccine stances. 

Cassidy has since criticized Kennedy and HHS’s decisions on vaccine policy. Last summer, Kenedy fired all previously serving members of a vaccine advisory panel, the Advisory Committee on Immunization Practices (ACIP), and appointed eight new members. The panel has since voted to end the recommendation that newborns receive the hepatitis B vaccine, a move Cassidy called “a mistake.” 

Trump celebrated Cassidy’s loss in a post on Truth Social, writing: “His disloyalty to the man who got him elected is now part of legend, and it’s nice to see that his political career is OVER!” 

In his concession speech, Cassidy made a pointed reference to Trump and his efforts to overturn his 2020 presidential election loss. 

“When you participate in a democracy, sometimes it doesn’t turn out the way you want it to,” he said. “But you don’t pout. You don’t whine. You don’t claim the election was stolen. You don’t manufacture some excuse. You thank the voters for that state or the country for as long as you’ve had that privilege.”   

Republicans control the Senate by a three-seat majority, 53 to 47, and senators serve six-year terms, meaning a third of the Senate is up every election cycle. For Democrats to win back the chamber in 2026, they’d need to hold on to every seat they have, including competitive ones in Georgia and Michigan. They also would have to flip four GOP-held seats — targets include Maine, North Carolina and even more Republican-leaning states such as Ohio, Iowa, Nebraska and Texas.