Trump tore into a GOP senator who said he wouldn't vote for him in 2024 and called for a senility test for US leaders

• President Donald Trump in a statement blasted Louisiana Sen. Bill Cassidy, a Republican.
• "He could not even be elected dog catcher today, the great people curse him," said Trump.

Former President Donald Trump blasted Sen. Bill Cassidy, after the Louisiana Republican cast doubt on Trump's prospects of winning the GOP nomination in 2024.

In the statement, Trump said Cassidy had "begged" for his endorsement in 2020 "and used it all over the place to win re-election."

"Now, Wacky Bill Cassidy can't walk down the street in Louisiana, a State I won by almost 20 points," the Monday statement read. "He could not even be elected dog catcher today, the great people curse him."

Trump was responding to an interview given by Cassidy to Axios, in which he criticized Trump's record and said he wouldn't vote for him if he ran again.

Cassidy noted that with Trump the GOP lost "the House, the Senate and the presidency in four years. Elections are about winning."

Later in the interview Cassidy, who is a physician, said he would like there to be senility tests for ageing leaders in all three branches of government.

"It's usually noticeable," Cassidy said of cognitive decline among politicians.

"So anybody in a position of responsibility who may potentially be on that slope, that is of concern. And I'm saying this as a doctor."

Trump will be 78 in 2024. The current president, Joe Biden, is 78. Allegations that he is in cognitive decline, usually seizing on verbal slips and without other evidence, are a frequent source of Republican attacks.

House Speaker Nancy Pelosi is 81 and Senate minority leader Mitch McConnell is 79.

Cassidy was one of seven Republican senators who voted to convict Trump in his impeachment trial over allegations he'd helped to instigate the January 6 riot. He is one of a small group of GOP lawmakers to openly oppose the former president in the wake of the violence.

Trump in recent weeks has endorsed primary challengers to Republican critics including Rep. Liz Cheney.

For months Trump, who remains enormously popular with the Republican base, has been stirring rumors that he'll make a bid to return to the White House in 2024.

He is considered favorite to be the Republican candidate if he does run.