Republican senator who voted for Trump impeachment loses re-election bid to president-backed challenger

A Trump-backed challenger has defeated a two-term Republican senator who voted to convict the president at his 2021 impeachment trial.

Congresswoman Julia Letlow will advance to a runoff next month, ousting incumbent Bill Cassidy, who President Donald Trump branded a "disloyal disaster" ahead of Louisiana's high-stakes contest on Saturday.

State treasurer John Fleming, another Trump-aligned candidate, also advanced to the runoff in the Republican primary.

As the top two Republican candidates, with neither winning a simple majority, Letlow and Fleming will face off again in late June. The candidate who wins the runoff will face a Democratic candidate for Senate in the general election.

Cassidy, 68, was one of seven Senate Republicans who voted to convict Trump when the president was impeached after the 6 January attack on the Capitol in 2021. Trump was acquitted after the Senate voted 57-43, short of the two-thirds majority required.

Of the seven Republicans who voted to convict him, only three still serve in the Senate: Lisa Murkowski of Alaska, who survived a primary challenge in 2022; Susan Collins of Maine; and Bill Cassidy.

Fleming previously was a representative for Louisiana in Congress and also worked in the first Trump administration. Letlow, 45, is the first Republican woman elected to represent Louisiana in Congress.

She won a special election for Louisiana's 5th Congressional District in 2021 after her husband, a newly elected representative, died in 2020 from complications related to Covid-19 before his swearing in.

Letlow has accused Cassidy of being disloyal to the Republican Party and has claimed that the people of Louisiana "shouldn't have to wonder how our senator will vote when the pressure's on".

She has echoed MAGA loyalist sentiment that Cassidy's vote to convict Trump was a betrayal.

During his re-election campaign, the Louisiana senator sought to repair his strained relationship with Trump.

"I don't really think President Trump likes me that much, but we work really well together," Cassidy told reporters last week, pointing to several bills he sponsored that were later signed into law by the president.

But despite his attempts to emphasise his alignment with Trump, the president in January encouraged Letlow to challenge the senator.

Just as polls opened in Louisiana on Saturday morning, Trump took another swing at Cassidy, and re-upped his support for Letlow.

"Bill Cassidy is a sleazebag, a terrible guy, who is BAD FOR LOUISIANA," the president wrote. "Now he's going to get CLOBBERED, hopefully, in today's BIG election, by two great people!!! VOTE TODAY FOR JULIA L. She Is a winner who will NEVER let you down."

Cassidy, who is a gastroenterologist, also faced criticism from right-wing opponents over his outspoken support for vaccines.

For his part, the incumbent senator has accused Letlow of not being conservative enough, highlighting comments she made in 2020 supporting diversity, equity, and inclusion programmes in education.