WASHINGTON (AP) -- Marco Rubio's strong third-place finish in Iowa could sound like a starting gun to the Republican Party's top donors.
For months, many of these benefactors have been sitting on the sidelines or spreading their money around to multiple presidential candidates as they waited to see whether one of four experienced politicians could rise up enough to take on political newcomer Donald Trump and conservative insurgent Ted Cruz.
Rubio, a 44-year-old Florida senator, came within striking distance of Trump's second place in Iowa, a surprising result given the celebrity businessman's dominance in polls. Rubio moves on to New Hampshire, which weighs in Tuesday, having picked up the same number of Iowa delegates as Trump, and just one fewer than Cruz.
"A lot of people who held back have now seen how real my candidate is," said Phil Rosen, a New York-based fundraiser for Rubio. Rosen said he'd received — unprompted — about 20 emails in the early hours Tuesday from people asking how they can give money to Rubio's campaign. "To me, it's a big, big sign that people are getting in touch without me having to make my solicitation," Rosen said.
As Rubio experiences an upswing, Jeb Bush is falling out of favor with key donors. That could eventually swing more money toward Bush's onetime protege.
"It's too late for Jeb Bush, and I think that's kind of sad," said Stanley Hubbard, a billionaire Minnesota broadcast executive. He'd previously expressed interest in giving a lot of money to outside groups helping the former Florida governor, Rubio or another GOP contender who rises up to take on Trump and Cruz.
Yet Hubbard said he has his eye on New Hampshire, where it's possible New Jersey Gov. Chris Christie or Ohio Gov. John Kasich could have a solid showing. "Let's see what happens next."
One of Bush's biggest boosters, Mike Fernandez, said he was "saddened" that his candidate finished under 3 percent in Iowa. Fernandez gave more than $3 million last year to an outside group backing Bush and separately paid for anti-Trump advertisements.
"I hope somehow he makes a miraculous comeback," the billionaire Miami health-care executive said of Bush. "There's obviously a disconnect between his campaign and what the people want."
Asked if he would consider backing a candidate other than Bush, he said, "I'm going to stay by his side until the very end."
Any donor momentum Rubio gains out of Iowa would build on efforts that seemed to be beginning late last year, fundraising reports filed Sunday night show.
He was the standout fundraiser among Bush, Christie and Kasich, the foursome that are vying for many of the same voters and donors. In the final three months of the year, Rubio raised roughly double what Bush had, even though he inherited a network of support from his father and brother, both former presidents.
Rubio dramatically outraised Christie and Kasich and began January with more cash on hand that any of those three, although the $10.4 million fell short of the $18.7 million Cruz had on hand.
Cruz eagerly noted that financial advantage as evidence he's the GOP candidate to beat.
"It's, frankly, unprecedented," Cruz told reporters Tuesday night on a flight from New Hampshire to South Carolina. "The conservative is supposed to be broke, and instead we've got the resources to compete nationally combined with a grassroots army from the ground."
Looking specifically at clusters of donors that make up the Republican Party "establishment" — power centers on Wall Street in New York and K Street in Washington — Rubio is increasingly dominant.
Two hedge fund billionaires, Paul Singer in New York and Ken Griffin in Chicago, gave a Rubio-boosting super PAC $2.5 million each late last year. Chris Cline, a coal executive, gave $1 million to the Bush super PAC Right to Rise through one of his limited liability companies. Four months later he wrote a personal check for $500,000 to Rubio's super PAC, Conservative Solutions.
Cline called both Bush and Rubio "excellent candidates" — but added, "Rubio is obviously a strong candidate."
"I am interested in the Republicans having the best possible candidate to face the Democrats in November," he said in an emailed statement.
Rubio's campaign reported more than $1 million that was raised by registered Washington lobbyists in the second half of 2015 — more than double what that group of people raised for Bush in the same time period.
Christie and Kasich raised barely anything via Washington lobbyists, the reports showed.