Casino mogul Sheldon Adelson and his wife, Miriam, are considering forming their own super PAC to direct their campaign contributions. (John Locher/Associated Press)

Efforts by potential Republican presidential candidates to win over wealthy donors have set off a series of contests for their support that could stall the GOP race for months.

In Florida, allies of former governor Jeb Bush and Sen. Marco Rubio are tussling over many of the same donors. In Texas, bundlers are feeling pulled by Bush, Gov. Rick Perry and Sen. Ted Cruz. Perry and Cruz are also competing for the backing of wealthy evangelical Christians, as are Indiana Gov. Mike Pence, Louisiana Gov. Bobby Jindal and former Arkansas governor Mike Huckabee.

Despite the appeals, which have stepped up in recent weeks, many top donors have committed to being noncommittal, wary of fueling the kind of costly and politically damaging battle that dominated the 2012 primaries. Senior party fundraisers believe that most campaigns will not be able to fully set up their fundraising operations until at least the spring.

A telling sign of the mood can be seen in the attitude of casino mogul Sheldon Adelson, one of the GOP’s biggest donors, who has expressed reluctance about engaging in the early primary fight. Instead, he and his wife, Miriam, are likely to set up their own super PAC to influence 2016 congressional campaigns as well as the White House race.

The hesitancy among the party’s financial patrons about jumping into the White House race right away could hamstring the ability of some candidates to ramp up their campaign operations and quickly break out of a pack of hopefuls that could number as many as two dozen.

From left, GOP backer Sheldon Adelson, Israeli American Council chairman Shawn Evenhaim and Hillary Clinton supporter Haim Saban attend the Israeli American Council Conference on Nov. 7 in Washington. (Shahar Azran)

Veteran fundraisers said there is a widespread desire among donors to pool their funds with other like-minded contributors, so as not to undercut their impact. Many are holding back from picking a candidate until Bush signals whether he will run.

With so many potential candidates — but no clear front-runner — the early maneuvering has had the effect of “just freezing” many donors, who are meeting with candidates but not making an early commitment, said Dan Senor, who advised GOP presidential nominee Mitt Romney in 2012.

“You would be hard pressed to find any invisible primary going back decades that was this fluid,” Senor said. “This is going to be chaotic and cluttered for some time.”

Establishment Republicans contemplating bids by figures such as Bush, Perry, Romney and New Jersey Gov. Chris Christie are pondering how to whittle the field to one of them, worried that a drawn-out primary process could produce a weakened GOP nominee.

“It’s really important for those donors who share the center-right philosophy to try to clear the field,” said Bobbie Kilberg, a longtime Republican fundraiser in Virginia who, with her husband, raised more than $4 million for Romney’s 2012 campaign. “We have to have one candidate we can all get behind.”

Doing their homework

The discussions are not just about rallying around a single candidate but also about how to pick the strongest one.

“There is a heightened awareness of the need for further and deeper homework on candidates and how they are going to win,” said one major GOP fundraiser who spoke on the condition of anonymity to describe private talks.

The upheaval on the right stands in stark contrast with the coalescing of major Democratic financiers behind the expected candidacy of former secretary of state Hillary Rodham Clinton. Operatives running a network of independent groups poised to flank her campaign began soliciting financial commitments the day after last month’s elections. Billionaire media mogul Haim Saban, a longtime Clinton backer, recently said he would spend “what­ever it takes” to get her into the White House.

The prospect of Clinton’s financial might has spurred anxious conversations among GOP donors about identifying early funding for the opposition-research group America Rising and others to take aim at Clinton while the Republican primaries are underway.

“There will be a coalition of people who are going to really focus on making sure the Democratic candidate is not able to take a huge advantage over the Republican, as happened in 2012,” said Ron Weiser, a former Republican National Committee finance chairman. “If Hillary is the Democratic candidate, she will be in a position of being able to define the leading Republican candidate long before it’s clear who has won. The same must be done to Hillary in order to be sure she doesn’t gain an advantage.”

The prospective 2016 candidates face more intense pressure than ever to raise substantial sums of money, with GOP strategists predicting that the winner will need at least $75 million to get through the first three primaries — and $1 billion by Election Day.

In a field of as many as 23 Republican candidates, raising that kind of money will not be easy.

“It’s a very large field of very competent candidates, and there’s just so much money to go around,” Kilberg said.

GOP White House hopefuls began reaching out to party donors in earnest as soon as this year’s midterm elections were over. Sen. Rand Paul (Ky.) held strategy sessions in Washington with advisers and supporters last month. Perry is inviting hundreds of wealthy Republicans to dinners he is holding in a tent outside the Austin governor’s mansion this month. Aides to Christie and Bush, among others, have individually contacted wealthy party backers.

The perennial discussions about assembling a national finance team have been accompanied by conversations about which billionaires will fund candidate-specific super PACs.

The Adelson effect

Wealthy donors such as Adelson “have an amazing ability to affect an outcome,” said one party fundraiser. “What if one of them plops $50 million into one of the primary candidates?”

At a gathering of major donors to the Republican Governors Association last month in Boca Raton, Fla., aides to some of the prospective candidates hinted to contributors that Adelson was behind them as a way to signal momentum, according to people in attendance.

In fact, while the casino mogul has been meeting privately with the top prospective candidates for months, he is holding off on making any commitments, his associates said. “He is meeting with everybody,” says Andy Abboud, his top political adviser. “But any decision about 2016 candidates is a long ways down the pike.”

This week, Adelson was scheduled to host a dinner in Las Vegas with Wisconsin Gov. Scott Walker and top Republican donors. The event follows private conversations he has had in recent weeks with Christie, Huckabee, Cruz and Jindal.

While Adelson and his wife assess the field, they are taking steps to dramatically change the way they spend their political money. After contributing nearly $100 million in 2012, largely to independent groups that backed GOP candidates, the couple are leaning toward setting up their own super PAC, as the New York Times first reported.

The decision to create an independent political operation follows an informal study by Adelson’s staff of spending in the 2012 and 2014 federal elections.

“We found a lot of inefficient and wasteful spending,” said a person close to Adelson,who asked not to be identified by name.

Adelson has become convinced that a shift to direct giving would permit the couple “to participate more directly in individual congressional campaigns without going through” the committees controlled by party leaders, the Adelson associate said.

Adelson is not alone in his cautious posture toward the 2016 White House race.

“The adage of jumping on the bandwagon early doesn’t apply this presidential cycle,” said Richard Hohlt, a Washington lobbyist who has served on the finance committees of GOP candidates since the days of Ronald Reagan. Hohlt has been attending meetings with potential 2016 candidates since the fall and says that he senses a noticeable hesitancy in the donor community.

“What most of us have learned in the last two cycles is that you need to verify the effectiveness of the campaign organization and the ability of the candidate to get across the finish line,” he said. “With so many candidates potentially running, most of us are thinking, ‘It is better to keep our powder dry.’ ”

Philip Rucker in Austin contributed to this report.