BOSTON (Reuters) - Many wealthy donors who gave the maximum allowable amount to Mitt Romney's presidential campaign have doubled down with big donations to an outside group backing the Republican's run for the White House.
A study released on Tuesday on the impact of the new, so-called Super PACS also showed some deep-pocketed donors giving to President Barack Obama.
Following a 2010 U.S. Supreme Court ruling, Super PACs can raise unlimited amounts of money from donors -- individuals, corporations and unions. They can use the money to fund political advertisements for or against federal candidates and to support or oppose candidates.
The 2012 election cycle will be the first time the Super PACS are major players on the U.S. political scene.
Figures from the Center for Responsive Politics, Democracy 21 and the Campaign Legal Center showed individuals gave from $3,500 to as much as $1 million to Restore our Future, the Super PAC created to promote Romney's candidacy.
The analysis showed that 55 of the 75 people who donated to Restore Our future had also given the maximum allowable amount to Romney's presidential campaign committee.
Individuals are allowed to give $2,500 per candidate, per election. Donations for a primary election and a general election are counted separately.
The double-dippers accounted for 73 percent of Restore Our Future's individual donors. They gave a combined $6.4 million, or 52 percent of the money raised by the Super PAC as of June 30 -- an average of about $116,000 per donor.
Romney, a former chief executive of private equity firm Bain Capital, has many well-connected backers in the financial industry and has held a series of fundraisers this year hosted by investment bankers and hedge fund managers.
The biggest donor to Restore Our Future was Edward Conard, a former managing director of Bain Capital.
Donations to Priorities USA Action, a Super PAC backing Obama, was dominated by one man. Jeffrey Katzenberg, CEO of DreamWorks Animation, gave $2 million of the $3.2 million raised as of June 30.
The study "demonstrates the largely uniform donor base shared by these ostensibly 'independent' Super PACs and the candidates they support," said Sheila Krumholz, executive director of the Center for Responsive Politics.
(Reporting by Ros Krasny; Editing by Peter Cooney)