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.