Julia Letlow (R) and John Fleming (R) advanced to a June 27 runoff in the Republican primary for U.S. Senate in Louisiana, with 45% and 28% of the vote, respectively. Incumbent Bill Cassidy finished third, with 24% of the vote.
President Donald Trump (R) and Gov. Jeff Landry (R) endorsed Letlow. According to Axios' Alex Isenstadt, heading into the election, "Cassidy — who voted to convict Trump over his role in instigating the Jan. 6 Capitol riot — is the only Republican senator Trump's team is targeting for defeat this primary season." Cassidy said, "I will continue to do a good job when I win re-election. I am a conservative who wakes up every morning thinking about how to make Louisiana and the United States a better place to live."
As of the 2026 election, Letlow represented Louisiana's 5th Congressional District. Letlow earned her bachelor's and master's degrees from the University of Louisiana Monroe and her doctorate from the University of South Florida. She worked as a university professor and administrator before her election to the U.S. House in 2021.
Letlow said she ran "to ensure the nation we leave our children is safer and stronger. Louisiana deserves a conservative Senator who will not waver. I am honored to have President Trump’s endorsement and trust." Letlow said in a campaign advertisement, "I have fought alongside President Trump to put America first -- standing up for our parents, securing our borders, supporting law enforcement, rooting out waste, fraud, and abuse that drives up inflation, and fighting to fix an education system too focused on woke ideology instead of teaching."
As of the 2026 election, Fleming was the Louisiana State Treasurer. Fleming earned his bachelor's degree and medical degree from the University of Mississippi. He served in the U.S. Navy and worked as a physician and business owner. He represented Louisiana's 4th Congressional District in the U.S. House from 2009 to 2017 and was Trump's deputy chief of staff at the end of Trump's first term.
Fleming told Louisiana First News' André Moreau that he had more experience than the other candidates: "I am a family physician ... Also I opened up a number of businesses that operate. ... I served eight years in the House of Representatives, I worked four years in the Trump administration. ... And then I've been your state treasurer for the last two years, so I'm bringing all that experience to this job." Fleming's campaign website said, "Now, John Fleming is running for the U.S. Senate to take that same conservative leadership to Washington — defending our values, securing our borders, protecting Louisiana jobs, and standing shoulder-to-shoulder with President Trump to put America First."
As of the 2026 election, Cassidy had been in the U.S. Senate since 2014. Cassidy earned his bachelor's degree and medical degree from Louisiana State University. He worked in charity hospitals and co-founded the Greater Baton Rouge Community Clinic. Cassidy was a state senator from 2006 to 2008. He represented Louisiana's 6th Congressional District in the U.S. House from 2009 until his election to the U.S. Senate.
Cassidy said, "The people of our state want safer streets, they want to be healthier, they want to have more money in their pocket. I have delivered that working with President Trump, over and over again. That’s what the race should be decided on." In an interview with KTBS, Cassidy described himself as "a conservative who's pro-life, pro-Second Amendment, pro-oil and gas, who's delivered for Louisiana."
Louisiana used closed party primaries for some offices in 2026, including the U.S. Senate, meaning Democrats and Republicans selected nominees for the general election. Previously, Louisiana used the majority-vote primary, commonly called a jungle primary. In that system, all candidates appeared on the same ballot and the top-two finishers advanced to the general election regardless of their party. A candidate who earned a simple majority of the vote in the primary won the election outright.
Thirty-three of the 100 U.S. Senate seats are up for election, and another two seats are up for special election. Democrats hold 13 of the seats up for election, and Republicans hold 22. As of April 2026, 11 members of the U.S. Senate announced they are not running for re-election.