“It’s a great day for Jeb Bush,” said Brian Ballard, a lobbyist who led Romney’s 2012 fundraising effort in Florida and switched to Bush this time around. “I think Jeb had 75 percent of the money folks here. This brings in the other 25 percent.”

Chicago private-equity executive Bill Kunkler and his wife, Susan Crown, had been top fundraisers for Romney in the last election and had expected to be there again for him in 2016.

Now, Bush is “the only one my wife and I will work for,” Kunkler said. “If it’s not Jeb, we’re done for this cycle. I know in my heart that Jeb is the only one who passes the presidential test. . . . We’ll be all in for him.”

But there will be plenty of competition for the big funders who built the massive Bank of Mitt in 2012.