Presidential candidates often keep a running list of influential individuals who they will informally call for ideas, advice, and, perhaps, to scope them out as a potential running mate.

And for several candidates, including at least one in the top tier, former Tallahassee Mayor Andrew Gillum is on speed dial. Sen. Elizabeth Warren (D-MA), in particular, has been in contact with Gillum over the past several months, multiple knowledgeable sources told The Daily Beast.

When reached for comment about the vice presidential buzz, a Warren campaign official said, “that is baseless and not at all true.”

But two sources said the talks between Warren and Gillum resemble the kind of courtship that happens when a leading presidential candidate is exploring potential vice presidential contenders. One source briefed on the communications said the two Democrats have been in contact over the course of the campaign and that there is a “strong impression” that Gillum is a possible vice presidential contender for Warren, who has risen in recent months to become a frontrunner in the 2020 primary, the source said.

“If you’re trying to win Florida, I would be courting Andrew and that’s what’s happening,” a second source familiar with the conversations said.

Others said the conversations are broader in scope and that Gillum, who narrowly lost a gubernatorial bid by less than a half a point to Republican Ron DeSantis in 2018, is a key player in the biggest battleground state, which President Donald Trump won by less than two percentage points in 2016.

A source close to Gillum’s political team would not confirm specific talks, but stated that Gillum is in communication with many of the candidates and noted that Florida is a critical state to win the presidency.

But hours after The Daily Beast posted this story, Gillum tweeted, "Many of my friends running to beat @realDonaldTrump call me often — about one thing: how to win Florida."

He then included a pitch and a link to his new effort to register 1 million new voters in Florida.

Gillum, 40, ran a tight race that attracted significant national attention in the height of the 2018 midterm elections, even bringing in former President Barack Obama to rally for him in Miami. But his race was dogged by Trump’s outsized influence in Florida and Trump himself, who attacked Gillum as a “socialist” and a “stone cold thief” in reference, Trump said on Fox News, to a federal corruption probe that ensnared top officials in Tallahassee. Gillum maintained that he was not the focus of the investigation and had done nothing wrong.

But even after his loss to DeSantis, Gillum’s name was among the rising Democratic stars listed as potential presidential material. After his announcement in March that he would not run for president, his name has continued to be part of the national conversation, primarily centered on his voter registration effort.

In 2018, several Democrats—who later launched 2020 bids—played an active role in boosting Gillum’s campaign. That includes former Vice President Joe Biden and Sen. Kamala Harris (D-CA), both of whom have been in touch with Gillum in recent months. Warren recorded a video endorsement for Gillum during his race, saying, “Andrew’s the leader the Sunshine State needs.”

Betsy Woodruff Swan contributed to this report.