Who will Donald Trump choose as his vice-presidential running mate?

With the Republican convention to formally nominate the party's presidential candidate around the corner, Donald Trump will be making his vice-presidential running mate selection soon enough.

Trump, the 2016 outsider candidate who upended the party, chose Mike Pence then. That political alliance ended when Pence refused to heed Trump's pleas to not officially certify Joe Biden's 2020 win, despite being threatened by some Trump supporters during the Capitol insurrection.

Political scientists have long said that vice-presidential choices have rarely had an impact on voting behaviour.

But the choices are always debated. Ahead of the July 15 convention in Milwaukee, Reuters has heard several names repeated based on conversations with nine people who have talked with Trump or his team in recent weeks, including donors, lobbyists and campaign operatives.

Here's a closer look at some potential VP candidates:

Burgum, 67, was little known outside his native North Dakota when he launched a quixotic campaign for president last year. The governor of the 47th most populous state in the U.S. since 2016, he gained attention for offering cash in exchange for donations in a brief campaign that involved spending at least $12 million US of his own money.

There a number of factors that could endear him to the nominee: he endorsed Trump right away after dropping out of the presidential campaign, he was among a small number of Republicans to travel to New York and protest Trump's trial outside the courthouse and he is a real estate investor and billionaire who sold a software company to Microsoft in 2001.

Trivia: There has never been a VP from the Dakotas.

Cotton, 47, has been in the Senate since 2015, and prior to that put two years in as a House member. He serves on the judiciary, intelligence and armed services committees. Perhaps the candidate would like another face on those committees, as Cotton was not averse to occasionally voting against the first Trump administration.

Cotton received a law degree from Harvard and then enlisted in the U.S. army, seeing active combat duty but later encountering criticism for allegations he mischaracterized aspects of his deployment. His op-ed imploring the Trump administration to send in troops to quell 2020 protests over police brutality famously caused a rupture within the New York Times.

More recently, Cotton gave a stronger statement in supporting the results of the upcoming election compared to some other potential VP candidates.

Trivia: Cotton is six-foot-five. Would Trump pick a VP taller than he is?

Rubio, 53, ran for president in 2016 and found himself on the end of several Trump insults, but any hard feelings have long since been smoothed over. Rubio was a strong backer when Trump was president, voting against his two impeachments, and he compared Trump's recent conviction to show trials in authoritarian countries. A Florida senator since 2010, he probably has the widest range of committee experience of any potential picks.

While going from being one of the most high-profile senators to a role that's often overshadowed might seem like a step back, Rubio is no doubt mindful of history — Richard Nixon and George H.W. Bush raised their profiles vice-presidents and landed in the Oval Office after previous failed presidential bids.