In private conversations, some said that after favoring the former governor early on, they were now taking a more serious look at the senator. One business leader, who requested anonymity for fear of alienating Bush, said there was an increasing sense that Rubio was simply a better communicator — and one who would carry the party’s banner more effectively in the general election.

“This is a group of people that, for the most part, likes Jeb. But there’s growing interest in Marco,” said Brian Ballard, a Tallahassee-based Republican lobbyist who is fundraising for Bush, acknowledging the chatter in the room. “The more people hear what he has to say, the more traction he gets.”

Bush acknowledges he’s in for a challenging campaign, even if he’s not ready to name Rubio specifically. “Look, it’s a rambunctious deal. We’ve got 75 people running I think, last time I checked? I hadn’t checked how many people announced today,” he joked on Tuesday while addressing the forum, which was held on the grounds of the Walt Disney Resort. “But it’s a big field. It’ll be competitive. There’s gonna be some elbows and knees under the boards. This isn’t tiddlywinks we’re playing.”