WASHINGTON - Campaign finance filings with the government now show that the cost of the 2012 U.S. presidential race has surpassed $2 billion, a new record.

The filings to the Federal Election Commission released Thursday, which include nearly $86 million in fund-raising by Republican presidential nominee Mitt Romney in the election's final weeks, boosted the total campaign haul over the $2 billion mark.

The campaign's record-breaking expenditures on media ads were fueled by eye-popping amounts donated to "super" political action committees, including at least $95 million supporting Romney and other Republicans that came from a billionaire Las Vegas casino magnate.

Casino owner Sheldon Adelson and his wife gave $23 million to a super PAC headed by GOP strategist Karl Rove and $10 million to a pro-Romney political committee in the final weeks.

By late October, both campaigns already neared $1 billion in expenditures, and super PACs supporting Obama and Romney had spent more than $500 million in media ads. Politically oriented nonprofit "social welfare" organizations that do not have to declare their finances or identify their fund-raisers have spent hundreds of millions more on so-called issue ads.

Adelson, who owns casinos in Las Vegas, Singapore, and the Chinese territory of Macau, has been the top donor in the 2012 race. He has provided more than $54 million supporting Romney and other GOP presidential candidates and an additional $18 million for other Republicans.

Adelson recently told the Wall Street Journal that he would double his $100 million investment in GOP causes by the next election and he has the financial muscle to do it.

Other top last-minute donors to the pro-Romney Restore Our Futre super PAC included Larry Ellison, head of software giant Oracle Corp., who gave $3 million, and Houston Texans owner Robert McNair, who gave $1 million. The Renco Group, a New York company headed by investor Ira Rennert, also gave $1 million.