"I think the vast majority of Jeb folks will join Marco," said Brian Ballard, a former Bush fundraiser who came over to Rubio's team. "I'm not having to sell hard. The case is clear and people want to join. They are joining as we speak."
But Texas Sen. Ted Cruz's campaign is also making a case for the cash.
"The Cruz campaign is very organized, very smart, and I think they have a strategy to go after as many of the Jeb finance and political people as they can," said Bush adviser Austin Barbour. "I can't imagine one Jeb Bush supporter is going to Trump. Not one."
Ohio Gov. John Kasich may also get a boost in the wake of Bush's exit from the race, but it may not do enough to raise his low polling numbers.
"To me, the only logical one is either Kasich or Rubio," Al Hoffman, former finance chairman for the Republican National Committee, told USA Today. "And poor John, I don't think he has enough to win that battle, so I guess my default has to be Marco. That would be a tough one not to argue."
"It seems to me most mainstream Republicans will rally to Rubio's side," said veteran GOP fundraiser Fred Malek, who's neutral in this fight. "He bridges the gaps and brings everybody together. Bush and Kasich could have done that, too. But they didn't come in second place in South Carolina."
Then there is the question of Right to Rise USA, the super PAC backing Bush that raised a whopping $103 million last year. According to the Federal Elections Commission, the PAC ended January with more than $24 million cash on hand. The Hill reported by now there is about $15 million remaining.
The super PAC's website still prominently asks supporters to support Bush's White House bid. One must scroll down to see the statement released by Right to Rise on Saturday saying: "We are ceasing our activities in support of Gov. Bush's nomination."
According to registration papers filed with the FEC, Right to Rise USA can back more than one candidate. If the group chooses not to back someone else, they can return the money to donors or give it to charity. Paul Lindsay, a spokesman for Right to Rise USA, did not respond to The Hill's request for comment.