It could be a loyal lieutenant, an ex-rival or perhaps a political newcomer, but one thing is certain: all eyes are on White House hopeful Donald Trump as he considers potential running mates.

A shrewd vice-presidential pick could help the Republican tycoon broaden his support base, and a handful of names have emerged as most likely to appear at Trump's side as he limbers for a second showdown with Joe Biden in November.

Here are the most commonly-cited runners and riders.

Tim Scott

It is no secret that Trump likes what Scott's profile says about the staunchly conservative, deeply religious African American US senator from South Carolina -- and what it would say about the Republican ticket.

The former president is constantly praising the 50-year-old, his one-time rival for the Republican nomination, for his loyalty.

"You're a much better candidate for me than you were for yourself," Trump told Scott at a recent rally.

With Scott as his right-hand man, Trump would hope to make inroads with Black voters, who largely preferred Biden in 2020.

But detractors criticize the senator for lacking the presence required to assert himself, particularly during debates.

Elise Stefanik

Stefanik, 39, was a considered a moderate when she entered Congress, but her lurch to the right during a meteoric rise to the Republican leadership can be explained in two words: Donald Trump.

The New York congresswoman has embraced all of the billionaire's causes, winning his approval and appreciation in return.

A Trump campaign with Stefanik on the ticket could win back some of the women that have turned away from Trump since his 2016 victory.

But the fervent Trump loyalist could also turn off more moderate voters.

J.D. Vance

Vance hasn't always been a fan of Trump, something the former president enjoys bringing up from time to time.

But count the 39-year-old former military officer out at your peril.

Known for a best-selling memoir on the travails of poor, white America, Vance entered politics relatively recently.

The first-term senator from Ohio has already made plenty of allies in Republican circles, not least because of his ability to raise large sums of money for his party.

In a country where election victories can cost billions of dollars, big fundraisers are rarely short of friends.

Marco Rubio

Trump and Marco Rubio have history.

The Florida senator was pitted against the real estate tycoon in the 2016 Republican primary, during which Rubio openly mocked his more popular rival over his complexion, and for having small hands.

But the former adversaries seem to have buried the hatchet.

Trump will weigh the potential for an electoral boost among Hispanic voters with the selection of the 52-year-old son of Cuban immigrants, who takes a keen interest in foreign policy.

A section of the hard right, however, has never forgiven Rubio for pushing immigration reforms more than 10 years ago that they saw as too liberal.

Nikki Haley

Trump's last rival in the Republican primaries would be a surprising pick indeed. But a Vice President Nikki Haley isn't out of the question.

The 52-year-old has yet to endorse the man who, during the final months of the primary campaign, referred to her as "birdbrain."

But the former South Carolina governor is popular with the moderates and independents that Biden is keen to wrest from the Republicans -- and that Trump would do well to court.

The chasing pack

North Dakota governor Doug Burgum and Florida senator Rick Scott have also been mentioned as possibilities, although -- as fellow rich, white men -- they would offer little contrast from Trump.

Vivek Ramaswamy -- the upstart newcomer who shook up the first Republican primary debate -- is also on the fringes of the conversation, alongside Congressman Byron Donalds, another Floridian, and firebrand former TV presenter Kari Lake.

Long seen as a credible contender, South Dakota governor Kristi Noem has seen her political stock plummet since she recounted having shot dead a pet dog she was unable to bring to heel.

AFP reached out to the Trump team for a hint on the kind of candidate that might turn the candidate's head. A campaign aide demurred.

"Anyone claiming to know who or when President Trump will choose his VP is lying, unless the person is named Donald J. Trump," he said.

© Agence France-Presse