By Steve Holland
WASHINGTON (Reuters) - In public, Republican presidential hopefuls Jeb Bush and Marco Rubio are moving from polite rivals to bickering combatants. Behind the scenes, their intensifying battle for donors since Scott Walker exited the Republican race may be a precursor of the next leg in the campaign.
Even with the exit of Walker, the Wisconsin governor, on Sept. 21, Bush and Rubio are among 15 Republican contenders, with the early nominating contests in Iowa and New Hampshire now four months away.
But the two, both from Florida, occupy the same party establishment turf in the 2016 campaign, and many Republicans believe their courtship of Walker's supporters is a quiet version of what will erupt into a full-bore battle - for cash and for voters.
By Oct. 15, the candidates must disclose their latest fundraising totals in a report that will offer a barometer of how they are doing in the competition for cash.
Many analysts think that Bush and Rubio could rise to the top if outsider favorites Donald Trump, Ben Carson and Carly Fiorina falter.
Bush, 62, is touting his experience as a governor who advanced conservative principles while Rubio, 44, is emphasizing his foreign policy knowledge gained in the Senate and the promise of a new generation of leadership.
The behind-the-scenes battle for money provides a glimpse into how the competition is playing out.
It was barely two days after Walker dropped out of the race when Anthony Scaramucci's phone rang. Bush, the former Florida governor, was on the line.
They chatted about how Walker was bearing up, then Bush got down to business.
"Listen, I could use the help," he told Scaramucci, a major Walker donor and New York investor. "I just want you on our team."
The conversation, recounted by Scaramucci in an interview with Reuters, was a factor in getting his support, but not the only one. Scaramucci liked Bush's executive experience and his emphasis on policy.
For Judson Hill, a Republican state senator from Georgia, it was easy to transition to Rubio after Walker pulled out. He had already had a one-on-one meeting with Rubio backstage after the U.S. senator from Florida spoke in Atlanta late last month.
He has found Rubio to be a "refreshing conservative leader who has a track record of experience." Plus, they made a personal connection in their conversation.
"I was born in Miami. He's from Miami. He knows the high school I graduated from on a personal level," Hill said.
In New Hampshire, whose presidential primary election on Feb. 9 will follow the Iowa caucuses, Cliff Hurst was grieving Walker's departure and wondering whether to back another candidate when he got a call from an old friend, Jim Merrill, who leads Rubio's organization in the state.
Hurst had met Rubio in 2007 when he traveled to New Hampshire to bolster support for Mike Huckabee, who was a Republican contender for the 2008 election. "I was impressed that he would come up from Florida in the winter when it was freezing and go door-to-door," Hurst said.
Hurst, a co-chairman of the New Hampshire Republican Party, decided to sign up with Rubio.
"The way you approach people and build relationships really matters," he said.
Sometimes one gets away, though.
Dallas biotech investor Chart Westcott, a former Walker supporter, had met Rubio at a Dallas fundraiser and liked what he heard. He was also approached by the Bush campaign.
He ended up throwing his support to Texas Senator Ted Cruz's presidential campaign.
"I wanted somebody who was going to go to Washington and completely shake the place up," he said.
Beyond the money lie the potential votes.
Walker was still giving his withdrawal speech in Wisconsin when, in Iowa, Chad Airhart's phone blew up with calls and text messages.
Airhart, an experienced hand in organizing the vote in Iowa's complicated caucuses - the first U.S. nominating contest on the road to the November 2016 election - had been a key backer for Walker.
Representatives from seven campaigns contacted him, including the campaigns of Bush and Rubio. He ended up switching his support to Bush in the days after Walker withdrew.
"He's a personable guy, not over-scripted. He's very knowledgeable on all the issues," Airhart said of Bush. "It's easy to close your eyes and imagine him as the president."