Trump cements grip on Republicans as ex-rivals fall in line

Donald Trump's failed primary challengers are to take the stage Tuesday at the Republican Party convention, in a display of fealty to its all-dominant champion and now official US presidential candidate.

The unified front comes a day after the ex-president triggered high emotion when entering the convention hall in Milwaukee as he made his first public appearance since surviving a weekend assassination attempt.

Three of Trump's political rivals turned endorsers -- Florida Governor Ron DeSantis, former UN ambassador Nikki Haley, and businessman Vivek Ramaswamy -- are to address the convention's 2,400 delegates Tuesday evening.

Haley, who just four months ago said the United States can't "go through four more years of chaos" under Trump, had not been expected to appear.

But Saturday's shooting at a Pennsylvania campaign rally reshuffled the deck, and Haley is now on Tuesday's speaking schedule along with Ramaswamy and DeSantis, a convention source said.

Seeking to reassure voters he remains robust despite the near-miss which injured his ear, Trump's team announced he will address a campaign rally on Saturday afternoon -- just one week on from the attack -- with his new vice presidential pick J.D. Vance.

Trump received a rapt ovation on Monday evening when he appeared with a bandage on his right ear, signaling how close he came to losing his life when a lone shooter on a roof fired at him.

On the other side of the country, meanwhile, President Joe Biden on Tuesday called for a ban on the type of semi-automatic rifle that was used in the attempted assassination.

"An AR-15 was used in the shooting of Donald Trump... It's time to outlaw them," the Democrat said during a campaign event in Las Vegas, adding: "Join me in getting these weapons of war off the streets of America."

- Momentum -

Trump on Monday had solidified the Republican ticket on day one of the four-day convention, announcing Vance, a 39-year-old US senator from Ohio and a one-time harsh critic turned uncompromising supporter, as his running mate.

Vance, who says his modest Rust Belt upbringing makes him a voice for working-class voters in left-behind America, is set to address the convention Wednesday evening, while Trump will formally accept the party's nomination in a prime-time speech Thursday.

The standard-bearer for a new kind of populism that has come to the fore under Trump, Vance is also one of the least experienced VP picks in modern history.

But he embraces Trump's isolationist, anti-immigration America First movement and is further to the right than his new boss on some issues -- including abortion, where he embraces calls for federal legislation.

- 'Crazy emotions' -

On the convention floor, delegate and Trump supporter Austin Utley of Texas said he experienced "all kinds of crazy emotions" when his political hero made an appearance.

"The fact that he's here two days after he got shot just shows why we all support him and why everybody's here, because he's a fighter," Utley told AFP.

Trump has also been seeking to corral additional support for his buoyant campaign, calling Robert F Kennedy Junior to see if the independent candidate would drop out and endorse the Republican.

On the call, leaked to social media Tuesday, Trump told Kennedy the graze on his ear from the shooting "felt like the world's largest mosquito."

Less than four months before election day some 50,000 Republicans have descended on the convention in Wisconsin, the state where the Republican Party was born 170 years ago.

While Trump, 78, is increasingly confident of a return to the White House -- despite multiple legal problems and two impeachments clouding his first term -- Biden is reeling from weak polls and Democratic concerns over his health.