Who are the big-money donors to the Obama, Romney campaigns?

Who are the biggest donors to the campaigns of President Barack Obama and Republican challenger Mitt Romney? The Associated Press examined more than 2.3 million campaign contributions and ranked the top five financial supporters for each.

Those donors and others are funding a presidential election on track to cost nearly $2 billion, with money going toward individual Democratic and Republican campaigns as well as independent, “super” political committees working on the campaigns’ behalf.

The largest declared donor overall is casino mogul Sheldon Adelson, who is worth an estimated $25 billion. He has donated $34.2 million so far to aid Romney and organizations supporting Romney this election.

All five of the top Romney donors gave more money than the top Obama donor, movie producer Jeffrey Katzenberg.

Big-dollar donors can have big influence. They are often invited to state dinners at the White House and other events with the president. They also may be asked to weigh in on public policy, especially if it affects their financial interests. And the ranks of ambassadors, advisory panels and other government jobs traditionally are filled with those who have been generous during the campaign.

Here are the top five Obama donors:

No. 1: Jeffrey Katzenberg, 61, Hollywood film producer and chief executive of DreamWorks Animation.

Total: $2.566 million

Katzenberg is Obama’s top donor when tallying his contributions to a “super” political committee, money to Obama’s campaign and the money he arranged for others to write for the president. The biggest contributions include $2 million to the Priorities USA Action super PAC. It was founded by former White House advisers and is the key pro-Obama PAC this election cycle. Katzenberg has helped “bundle” more than $500,000 for the president’s second term, making him among the campaign’s top volunteer fundraisers. He’s also given more than $66,000 to Obama’s campaign and the Democratic Party. The Hollywood icon has been invited to White House events, including a state dinner. Such high-profile soirées put him in proximity earlier this year to Chinese Vice President Xi Jinping, who signed off on an overseas deal benefiting Katzenberg’s studio.

No. 2: Irwin Jacobs, 78, the founder and former chairman of Qualcomm.

Total: $2.122 million

Jacobs has given more than $2 million to pro-Obama super PACs and about $23,000 directly to Obama’s campaign and the Democrats. But he’s no newcomer to political giving: The billionaire has routinely backed San Diego-area politicians. Some of his local proposals include one backed by San Diego’s mayor that would have changed the name of Qualcomm Stadium for 10 days to reflect the cellphone maker’s new computer chip.

No. 3 (tie): Fred Eychaner, founder of Chicago-based alternative-newspaper publisher Newsweb Corp.

Total: $2.066 million

Eychaner has given $1.5 million to the Priorities USA Action super PAC. He’s also given more than $60,000 to the president’s re-election committees, and he’s listed as a major “bundler” for Obama, having raised at least $500,000 for the president. Eychaner, a gay-rights activist, also has donated millions to other nonprofit groups, including more than $1 million to the progressive EMILY’s List organization. He’s visited the White House several times since early 2009, according to records, and Obama appointed Eychaner to the board of trustees of the John F. Kennedy Center for the Performing Arts.

No. 3 (tie): Jon Stryker, 54, a Michigan philanthropist.

Total: $2.066 million

Stryker has given $2 million to the Priorities USA Action super PAC and has given $66,000 in contributions to Obama and the Democratic Party. Stryker is the heir to namesake Stryker Corp., the major medical device and equipment manufacturer. Stryker has been active in politics before the 2012 election; he contributed millions to help Democratic candidates statewide. And he also has given nearly $250 million of his personal wealth to groups supporting gay rights and the conservation of apes.

No. 5: Steve Mostyn, 41, a Houston-based personal injury attorney.

Total: $2.003 million

Mostyn has given more than $2 million to the Priorities USA Action super PAC that’s helping Obama. Mostyn, the former head of the Texas Trial Lawyers Association, is a major backer of Democratic candidates in the state. He’s also sank cash into a Texas political committee that tried unsuccessfully to unseat Gov. Rick Perry two years ago.

Here are the top five Romney donors:

No. 1: Sheldon Adelson, 79, owner of the Las Vegas Sands casino empire.

Total: $34.2 million

Adelson is the largest declared donor to the Romney campaign and supporting political committees, providing more than $34.2 million this election season. He and his wife, Miriam, a physician, have given $10 million to the Restore Our Future, a super PAC backing Romney. Adelson also joined relatives to give $24 million to committees backing former Republican presidential candidate Newt Gingrich. And he has made public pledges vowing to give $10 million to Karl Rove’s American Crossroads super PAC and as much as $100 million this election more broadly to the Republicans. Worth an estimated $25 billion, Adelson oversees the Las Vegas Sands Corp., which runs casino and resort interests in Las Vegas, Singapore and Pennsylvanis, and Sands China Ltd., a cluster of casinos in the Chinese territory of Macau. He would benefit from loosened trade restrictions and a rise in the Chinese currency rate against the dollar. His company devoted $60,000 this year to lobby on tax issues, foreign tourist visas, travel and Internet gambling issues – and has spent $1.86 million lobbying on legislation dealing with China trade, gambling and travel since 2002. A staunch supporter of Israel, he also is a contributor to the Republican Jewish Coalition, which spent $920,000 since 2002 backing bills aimed at pressuring Iran and enhancing U.S. security cooperation with Israel. Adelson’s casino company has advised shareholders that it was under investigation by the Justice Department and the Securities and Exchange Commission. Investigators were said to be focusing on the Macau casinos and reports of missing money and possible violations of the Foreign Corrupt Practices Act.

No. 2: Bob J. Perry, 80, head of a Houston real estate empire worth an estimated $650 million.

Total: $17.3 million

Perry had been at No. 3, after giving $15.3 million to aid the Romney campaign and allied causes so far this election season. But federal campaign figures released Friday showed a new $2 million donation to Restore Our Future in September, vaulting Perry into the No. 2 spot. Long active in Texas and national Republican politics, Perry has donated a total of $10.7 million to Restore Our Future and $6.5 million to American Crossroads. Before backing Romney this year, Perry gave $100,000 to the super PAC backing Texas Gov. Rick Perry, who is no relation. Bob Perry was a top “bundler” for former President George W. Bush’s campaign and gave big to the Swift Vets and POWs for Truth campaign in 2004, donating $4.4 million to the effort to discredit Kerry.

No. 3: Harold Simmons, 81, owner of Contran Corp., a Dallas-based conglomerate worth an estimated $9 billion that specializes in metals and chemical production and waste management.

Total: $16.5 million

Simmons is a longtime backer of Republican and conservative causes. He has donated $16 million to the party’s efforts this year, including more than $11 million to American Crossroads and $1.3 million to Restore Our Future. Simmons and his wife, Annette, also gave $2.2 million to super PACs backing former Republican presidential candidates Gingrich, Rick Santorum and Rick Perry. Simmons has been active in political fundraising since the 1990s and in 2004 was a $4 million backer of the Swift Vets campaign, the Republican-backed effort to discredit Democratic presidential nominee John Kerry’s military record in the Vietnam War. Simmons’ Titanium Metals Corp. reportedly is a top producer of titanium for weapons and other industrial uses. He also owns a majority stake in Valhi Inc., a Texas-based waste management company, and could benefit from a proposed Nuclear Regulatory Commission rule change that would allow the company’s Texas facility to store spent uranium from nuclear power and weapons plants. Contran’s subsidiaries have spent $200,000 this year lobbying the NRC, Energy Department, the Senate and House on metals and waste issues, and $4.3 over the past decade.

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.

No. 5: William Koch, 72, an industrialist whose South Florida-based energy and mining conglomerate is worth an estimated $4 billion.

Total: $4 million

Koch has given $4 million to the Restore Our Future, including a $250,000 personal donation and $3.75 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 Republican 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.

METHODOLOGY

These rankings by The Associated Press, based on campaign financial reports submitted to the Federal Election Commission, include contributions to super political action committees, 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 Obama. Obama periodically identifies his bundlers, although Romney has resisted calls to do the same.