A challenger endorsed by Donald Trump has defeated Senator Bill Cassidy in Louisiana's Republican Senate primary. The two-term senator, over five years ago, voted to impeach Trump following the January 6, 2021, Capitol riot.

Following Cassidy's defeat, Trump posted on his Truth Social platform, stating: "His disloyalty to the person who helped get him elected is now the joke of politics. Glad to see his political career come to an end!"

In his concession speech, Cassidy drew a comparison between himself and Trump, who falsely claimed victory in the 2020 election and has denied responsibility for the Capitol violence.

Cassidy remarked, "Participating in democracy means sometimes you don't get the outcome you want. But you don't throw a tantrum, and you don't claim the election was stolen."

He added that those who "try to use the levers of power to control other people, they serve themselves, not the people. They don't deserve to be leaders."

This victory marks the latest in a series of primary wins for Trump as he works to eliminate political opponents.

Earlier this month, Trump successfully ousted five state senators in Indiana who opposed him over the state's congressional redistricting.

Another significant test will occur on Tuesday, with Trump and his allies aiming to remove Republican Representative Thomas Massie, who has clashed with Trump on issues such as the handling of the Jeffrey Epstein case.

Cassidy fell out of favor with Trump after voting to convict him in his second impeachment trial over five years ago, which focused on Trump's role in the January 6 Capitol riot and efforts to overturn the 2020 election results.

Last year, as chairman of the Senate Health, Education, Labor, and Pensions Committee, Cassidy questioned Trump's nominee for health secretary, Robert F. Kennedy Jr., over vaccine skepticism, further angering Trump's "Make America Great Again" (MAGA) base.

Cassidy, a physician, ultimately voted to support Kennedy's nomination, but this key endorsement did not regain Trump's favor. In January, Trump endorsed challenger Julia Letlow against Cassidy, who officially launched her campaign two days later.

Letlow was first elected to the House in a January 2021 special election. Her husband, Luke Letlow, was elected to Congress in November 2020 but died of COVID-19 the following month before being sworn in.

Cassidy was one of seven Republican senators who voted to convict Trump in the 2021 impeachment trial. Only Susan Collins of Maine and Lisa Murkowski of Alaska remain in the Senate from that group; the other four chose not to seek re-election to avoid provoking Trump's MAGA base.

Trump and the Republican Party face a tough battle to maintain control of both the House and the Senate in the November midterm elections.

With voter dissatisfaction over the war in Iran and persistently high U.S. living costs, the president's approval ratings have hit record lows. Polls indicate Democrats hold a solid advantage heading into the November elections.

Earlier this month, polls showed Democrats leading Republicans by 8 percentage points among all registered voters ahead of the midterms, with an even larger lead among independent voters.