No. 3: Bob J. Perry, 80, head of a Houston real estate empire worth an estimated $650 million.
Total: $15.3 million
Perry has given about $15.3 million to aid the Romney campaign and allied causes so far this election season. Long active in Texas and national GOP politics, Perry donated nearly $9 million to Restore Our Future and a total of $6.5 million to American Crossroads. Before backing Romney this year, Perry gave $100,000 to the super PAC backing Texas Gov. Rick Perry (no relation). Bob Perry has been a fixture of GOP fundraising in Texas and nationally dating back to former President George W. Bush's Texas gubernatorial races in the mid-1990s. Perry was a top Bush presidential "bundler" and also gave big to the Swift Vets and POWs for Truth campaign in 2004, donating $4.4 million to the effort to discredit Kerry.
No. 4: Robert Rowling, 58, head of Dallas-based TRT Holdings.
Total: $4.1 million
Rowling has given at least $4.1 million to Republican Party and candidates this election. Most of his donations, $4 million, went to Rove's American Crossroads, both through personal donations and through his firm. Rowling also has given $100,000 to the pro-Romney Restore Our Future super PAC. Rowling's holdings are worth an estimated $4.8 billion and include Omni Hotels, Gold's Gym and Tana Exploration, his family's oil company. Rowling once told the Texas Tribune he prefers political donations to lobbying efforts. Rowling has been a big donor in Texas political circles, winning a role for Omni as operator of Dallas' convention center hotel after a 2009 city referendum fight.
No. 5: William Koch, 72, an industrialist whose South Florida-based energy and mining conglomerate is worth an estimated $4 billion.
Total: $3 million
Koch has given $3 million to the Restore Our Future, including a $250,000 personal donation and $2.75 million through his corporation, Oxbow Carbon LLC, and a subsidiary, Huron Carbon. Unlike his brothers, Charles and David Koch, who are longtime supporters of Republican and conservative causes, Bill Koch has funded both GOP and Democratic Party candidates in the past. Koch's corporate interests have repeatedly battled against what company officials have decried as government interference. Oxbow spent $570,000 last year on lobbying in Washington, mostly aimed at mining, safety issues and climate change. The company has complained in federal filings about government delays on permits and has raised concerns about administration changes in regulations that would aid collective bargaining. Koch also has pushed for approval of the Central Rockies Land Exchange, a proposed swap of land tracts in Colorado and Utah to enlarge his 4,500-acre Bear Ranch. The proposal, which requires congressional approval, has sparked local opposition.
These rankings by The Associated Press, based on campaign financial reports submitted to the Federal Election Commission, include contributions to super PACs, presidential campaigns, political parties and joint-fundraising committees. Federal law limits maximum contributions to campaigns, parties and affiliated committees, but federal court rulings have stripped away such limits to super PACs. This analysis excludes secret-but-legal contributions that might have been made to nonprofit groups, which can pay for so-called issue ads that don't explicitly advocate for or against a candidate. Such groups are not required to identify their donors.
Where available, the analysis considered donations "bundled," or raised, from other wealthy donors for Romney and President Barack Obama. Obama periodically identifies his bundlers, although Romney has resisted calls to do the same.