By Alina Selyukh
WASHINGTON (Reuters) - If Mitt Romney wins the Republican presidential nomination, he will have the backing of several wealthy donors who together have contributed millions of dollars to his rivals in the race.
The donors, some of the big-money players behind the unprecedented spending in the state-by-state race for the Republican nomination, quietly have pledged to back Romney if their initial choice isn't the nominee, one donor himself and sources close to other donors said.
The donors include Dallas billionaire Harold Simmons and Houston homebuilder Bob Perry, supporters of Texas Governor Rick Perry before he dropped out of the race last month. Also pledging conditional allegiance to Romney: Las Vegas casino mogul Sheldon Adelson, whose family has donated nearly $11 million to support Newt Gingrich; and Foster Friess, a Wyoming investor who is Rick Santorum's chief benefactor.
Sources close to each donor say that in accepting Romney as a consolation candidate, the financiers are united by one idea: a desire for the Republican nominee to defeat Democratic President Barack Obama in the November 6 election.
Adelson's "overriding objective is to defeat Obama," said Fred Zeidman, a friend of Adelson and a fundraiser for Romney. "He's allocated a tremendous amount of money to getting Obama out of the White House."
The donors' conditional commitments underscore the potential impact of "Super PACs," the independent political groups that can swiftly raise and spend unlimited amounts of money, and influence the campaign by flooding TV and radio with ads.
In previous election cycles, such well-connected financiers were crucial to campaigns partly because of their ability to hold fundraisers and "bundle" together groups of donations to campaigns. In 2008, donations by individuals were limited to $2,300 in the party nominating contest, and the same amount in the general election.
Donations to campaigns are still restricted -- this year's limit is $2,500 for each election cycle -- but a 2010 Supreme Court ruling that allows unlimited spending by unions, corporations and other groups has blown the top off the nation's campaign finance system.
In the last few months, Simmons, Perry, Adelson and Friess have poured money into Super PACs, helping to fuel a spending spree by Republican groups that frequently has altered the trajectory of the race.
The biggest-spending group has been Restore Our Future, which supports Romney and has dumped more than $18 million into ads -- the vast majority of them attacking Gingrich, who until Santorum's recent rise was widely viewed as Romney's chief rival for the nomination.
The conditional commitments to Romney also could help the former Massachusetts governor match the fundraising firepower of Obama, who will face the Republican nominee in the November 6 elections.
Obama's campaign had raised almost $97 million by the end of last year, far more than any of the Republican campaigns. However, Priorities USA, the PAC that supports Obama, had raised a relatively paltry $4.2 million.
Most wealthy Democratic donors have yet to kick in donations because Obama was slow to encourage such contributions and has not had an opponent in the primaries.
"When they see what the eventual (Republican) nominee's Super PAC can do, they'll step up," said Republican strategist Ford O'Connell, who worked on the 2008 presidential campaign of Republican Senator John McCain against Obama. "The Obama campaign realizes they need a Super PAC because it's a weapon and he really needs every weapon in his arsenal."
"I'M VERY COMMITTED"
Simmons, the Dallas billionaire, has been a particularly active donor to Republican causes under the new system that allows unlimited contributions to PACs.
He personally gave $500,000 to the pro-Gingrich Super PAC and $5 million to American Crossroads, a PAC set up by Republican strategist Karl Rove aimed at helping Republican candidates for the White House and Congress.
Contran Corp., one of Simmons' companies, gave another $2 million to American Crossroads and $1 million to Make Us Great Again, the PAC that supported Rick Perry.
Simmons and Bob Perry also are familiar with hardball politicking.
In 2004, the duo gave millions of dollars to Swift Boat Veterans for Truth, a group that helped undermine Democratic presidential nominee John Kerry by attacking his Vietnam War record.
Bob Perry "will be strong with Romney; (Simmons and Perry are) both going to be there for the nominee," said one person familiar with Bob Perry's thinking and political fundraising in Texas.
Friess, the outspoken investor who gave $331,000 to the pro-Santorum Red, White and Blue Fund last year and another undisclosed sum this month, said in an interview that he "absolutely" would donate to Romney's effort if Santorum, a former Pennsylvania senator, fails to win the nomination.
"I'm very committed to whoever gets it," Friess said.
On the Democratic side, a big question surrounding Priorities USA is whether billionaire investor George Soros will dive in with a large donation to help Obama's re-election effort.
"He will make federal hard-dollar contribution to Obama's presidential campaign," Soros spokesman Michael Vachon said in an e-mail. "He is undecided about whether he will contribute to existing Super PACs."
Obama, who opposed the Supreme Court decision that spawned Super PACs, initially kept a distance from Priorities USA.
That changed amid concern that the eventual Republican nominee and his supporters could outspend the president's campaign in the general election, despite Obama's fundraising strength. Now, top officials in the Obama campaign are allowed to appear at Priorities USA events.
"The Super PACs are going to make up any ground between the president and his challenger," said Anthony Corrado, a campaign finance analyst and professor at Colby College in Maine.
"The question is now whether there were major Democratic donors just waiting on the sidelines for a call from the president, or if there's not excitement on the Democratic side among the wealthiest donors."
(Editing by David Lindsey and Cynthia Osterman)