The 2024 presidential election is expected to be another close and vicious race, and speculation is brewing about who Donald Trump will choose to maximize his advantage.

A new poll reported exclusively by The Daily Mail found that one candidate in particular would broaden Trump's appeal the most, former rival and Florida senator Marco Rubio (R).

Trump's ideal VP pick?

Rubio, a foreign policy hawk with a traditional Republican pedigree, battled with Trump for the nomination in 2016 but has since mostly supported the former president.

With Rubio on the ticket, Trump would peel off 6% of Democratic voters, the poll of 1,000 voters by J.L. Partners found.

Vivek Ramaswamy, a vocal Trump defender known for his provocative style, would bring 88% of Republicans home to Trump but energize Democrats at the same time.

Given Trump's dominance among GOP voters, he may be better served by trying to broaden his appeal, James Johnson, cofounder of J.L. Partners, said.

"Though the numbers are tight, our ballot tests with different VP candidates show that different options give a range of paths for Trump, some more optimal than others," he said.

"Ramaswamy, for example, is best to shore up support amongst Republicans and Independents alike, though with Trump’s dominance in the Republican base, there might not be much benefit to the former," he said.

"The VP candidate with the widest reach does appear to be Marco Rubio: He does best amongst non-graduates, women, and over-65s, the latter two groups being key defence areas for Republicans in the coming election," he said.

VP speculation explodes

Trump has cast a wide net, leaving the country guessing about who will win his favor.

The possible names run the gamut from newcomers like J.D. Vance and Vivek Ramaswamy to well-established politicians like Marco Rubio and Tim Scott.

A possible factor is the politics of abortion. It is unclear how solidly pro-life VP contenders will fare after Trump made a pivot to the middle on the contentious issue earlier this month.

Trump's team has stressed that only Trump knows who he will choose. But that hasn't stopped the rumor mill from churning.

Rubio is currently barred by residency issues from serving on the same ticket as Trump, since they both live in Florida.

But it's hard to imagine that standing in the way of Rubio's ambition.

"It's pretty clear from Trump's orbit that Rubio is in play," a Florida GOP operative told CNBC last month. "It makes sense because he checks almost every box if they can get past both being from Florida."