WASHINGTON -- Five wealthy people, led by Dallas industrialist Harold Simmons and Las Vegas casino mogul Sheldon Adelson, have donated nearly $1 of every $4 flowing to the super PACs raising unlimited money in this year's presidential race, a USA TODAY analysis shows.
Those donations have helped new Republican-leaning outside groups swamp Democratic-friendly super PACs in fundraising - money that is used largely for attack ads. The large sums also have rejuvenated the underfunded campaigns of principal challengers to former Massachusetts governor Mitt Romney in the race for the Republican nomination.
"Without the flow of super PAC money, the Republican race would be over," said Anthony Corrado, a campaign-finance expert at Colby College in Maine. "Super PACs have become a vehicle for a very small number of millionaires and billionaires who are willing to spend large sums in pursuit of their political agenda."
Simmons, a billionaire who pumped $3 million into "Swift Boat" ads in 2004 challenging Democrat John Kerry's Vietnam War record, is the largest super PAC donor of the 2012 election, the analysis shows.
He and his holding company, Contran, gave $12 million to American Crossroads, a super PAC affiliated with Republican strategist Karl Rove. He donated $2.2 million more to three super PACs supporting Republican presidential candidates. He did not respond to an interview request Tuesday.
In the No. 2 slot: Adelson and his wife, Miriam, who gave $10 million to Winning Our Future, a super PAC aiding former House speaker Newt Gingrich. Adelson declined an interview request through a spokesman.
However, in a Forbes magazine article posted Tuesday, Adelson said he is willing to donate an additional "$10 million or $100 million" to aid Gingrich. "I'm against very wealthy people attempting to or influencing elections, but as along as it's doable, I'm going to do it," Adelson said.
Adelson, who operates the Venetian, a massive Las Vegas resort, along with casinos in Singapore and Macau, shares hawkish stands on Israel with Gingrich, but he said he's motivated by economic policy. He said his goal is to defeat President Obama and what he termed a "socialist-style economy."
Other mega-donors to super PACs:
•Peter Thiel, a Silicon Valley venture capitalist and co-founder of PayPal, who donated $2.6 million to Endorse Liberty, a super PAC helping Rep. Ron Paul of Texas. Thiel, a libertarian, gave $70,000 to a 2010 ballot initiative in California legalizing marijuana.
Thiel is the single largest donor to Endorse Liberty, which has spent more than $3 million - mostly on Internet ads - to advance Paul's candidacy. "Men and women who want freedom and growth should take action," he said. "A good place to start is voting for Ron Paul."
•Houston home builder Bob Perry has donated $3.6 million to super PACs since Jan. 1, 2011, including $2.5 million to American Crossroads.
He has supported Texas Gov. Rick Perry and state PACs backing former Minnesota governor Tim Pawlenty in the past, but he shifted last year to a pro-Romney super PAC with a $1 million donation.
Anthony Holm, a spokesman for Bob Perry, released this statement about the contributions: "Bob Perry believes Mitt Romney is the right person to create jobs in America, which stands in stark contrast to our current president."
Simmons, whose vast holdings include chemical plants and an East Texas nuclear-waste facility, and Perry, one of the nation's largest home builders, have different business interests but share common political views, said Cal Jillson, a political scientist at Southern Methodist University in Dallas and author of Lone Star Tarnished: A Critical Look at Texas Politics and Public Policy.
"They are extremely wealthy people who put their resources behind their vision of the appropriate relationship between the government and the private sector," Jillson said. "That vision is low taxes, small government and personal responsibility."
No Democratic donors rank as high as the top donors to Republican super PACs.
Priorities USA Action, the main super PAC backing Obama's re-election, raised just shy of $59,000 in January - a fraction of the $27.2 million raised last month alone by five leading GOP super PACs. The biggest donation to Priorities USA Action last month: $50,000 from John Rogers, CEO of Ariel Investments and one of Obama's closest friends.