Updated May 16, 2026, 10:47 PM EDT By NBC News What to know tonightCASSIDY LOSES: Republican Sen. Bill Cassidy loses his primary as Rep. Julia Letlow and state Treasurer John Fleming advance to a June 27 runoff.CASSIDY'S CHALLENGE: Cassidy had been staring down a potentially difficult primary since 2021, when he was one of seven GOP senators who voted to convict Donald Trump on impeachment charges. He has also sparred with the Trump administration and Health and Human Services Secretary Robert F. Kennedy Jr. on vaccine policy and other public health issues in the last year-plus.THE FIELD: Trump endorsed Letlow in January, but Fleming has touted his own connections to the president. 16m ago / 10:47 PM EDTCassidy loses GOP primary in Louisiana, as two rivals advance to a runoffSen. Bill Cassidy, who voted to convict President Donald Trump on impeachment charges in 2021, has lost his Republican primary in Louisiana, as two challengers who had aligned with Trump advanced to a runoff.Rep. Julia Letlow, who had Trump’s endorsement in the race, will face state Treasurer John Fleming in a June 27 primary runoff, NBC News projects.Cassidy’s loss further cements Trump’s grip on the GOP as the president looks to exact revenge against Republicans who have crossed him in the past. And it also means another Republican who voted to convict Trump during his 2021 impeachment will not be returning to Congress next year. Follow live results here.33m ago / 10:29 PM EDTHere's why Trump holds a grudge against CassidyCassidy is in the fight of his political life today, trying to fend off two challengers, including one who has been endorsed by Trump.Cassidy, who is seeking a third term in the Senate, has drawn the president’s ire several times over the years.Nicholad Kamm