Fueling Mitt Romney’s fundraising surge has been a widely used but less understood tool enabling supporters to direct more money to his presidential effort than federal limits would suggest possible.

Individuals are limited to contributions of $2,500 to Romney for President and $30,800 to the Republican National Committee. But through the Romney Victory Inc. joint fundraising committee, which raised $140 million in the second quarter, maxed-out Romney and RNC donors can contribute to the Republican parties of Idaho, Massachusetts, Oklahoma and Vermont. There, the money will await redistribution to state parties in presidential battlegrounds as determined by team Romney and the RNC.

“It’s a way to help more within a legal framework,” said a Washington-based Republican fundraiser who is not affiliated with the Romney campaign.

Also included in the Romney Victory joint fundraising committee are the National Republican Congressional Committee and the National Republican Senatorial Committee, in part because donors who work in the finance industry are legally prohibited from donating to entities, such as state parties, that might fund or support the political activities of officials elected at the state level. Accordingly, portions of contributions to Romney Victory could flow to the NRCC and NRSC in the months ahead.

Romney Victory reported expenditures of $82.6 million during the second quarter and ended June with $57.7 million in cash on hand. During the same period, the committee’s expenditures included transfers of $68.8 million to participating committees, including $15.7 million to Romney for President, $53 million to the RNC and $20,000 each to the Republican parties of Idaho, Massachusetts, Oklahoma and Vermont.

Republican fundraisers and GOP sources with experience on presidential campaigns expect these four state parties to serve as conduits for possibly millions of dollars, collectively, between now and the Nov. 6 elections. These states are not competitive — Romney will easily win Idaho and Oklahoma, and President Barack Obama will cruise in Massachusetts and Vermont — and as such have virtually no use for the extra money.

That, and the close relationship the Romney campaign has with leaders of these state parties, is why they were chosen for the joint fundraising committee. This arrangement gives team Romney and the RNC maximum control and flexibility to direct money to the states of their choice throughout the fall. State parties in contested battlegrounds that need the money might spend it on activities not approved by team Romney in Boston or the RNC, while a poorly managed party might squander the funds altogether.

“I guarantee the reason they’re asking for those is [because] they can control them,” said a national Republican fundraiser who has previously advised GOP presidential candidates, regarding the Romney campaign’s decision to include the Idaho, Massachusetts, Oklahoma and Vermont state parties in the joint fundraising committee.

“If too much went to Ohio, they would not share,” added a Republican operative who has contributed to Romney Victory.

The Obama campaign and the Democratic National Committee also are using a joint fundraising committee to stockpile and distribute cash. In the second quarter, Obama Victory Fund 2012 raised $76.5 million and spent $71.2 million, closing the period with $9 million in cash on hand. As of June 30, Obama’s joint fundraising committee had raised $221.4 million to date for the cycle, according to its July FEC report.

But in designating state Democratic parties in 10 presidential battlegrounds as joint committee participants, the Obama campaign appears to have made a different strategic calculation regarding resource allocation than the Romney campaign. State party affiliates include those in Colorado, Florida, Iowa, Nevada, New Hampshire, North Carolina, Ohio, Pennsylvania, Virginia and Wisconsin. The Romney and Obama campaigns both declined to comment. But the president’s campaign did confirm the entities participating in their joint committee, which also include Obama for America and the DNC.

From April 1 to June 30, none of the affiliated state Democratic parties received transfers from Obama Victory Fund 2012. Meanwhile, Romney Victory only began raising money in April, once it became clear the former Massachusetts governor would win the nomination. Republican operatives interviewed for this story say they expected Romney to raise plenty of money but emphasize that even they are surprised at how much he has brought in — and how fast.

“It’s amazing that they’re clipping such big checks,” said the national Republican fundraiser who has advised GOP presidential candidates.

Romney Victory fundraisers offer escalating perks depending on how much an individual or married couple contributes. Large donations are generally distributed among the participating committees this way: The first $2,500 goes to Romney for President’s primary campaign account, the second $2,500 goes to the campaign’s general election account, the next $30,800 goes to the RNC, and the remaining amount is spread to the affiliated state parties or the NRCC and the NRSC.

Campaign finance regulations limit donations to federal candidates and political parties to a maximum of $117,000 per election cycle, including a maximum of $46,200 to candidates and $70,800 to political parties and political action committees. Although Romney Victory accepts contributions at all levels, one of its chief targets is wealthy couples who can afford to give anywhere from $50,000 to $70,000 ($25,000 to $35,000 each).

A GOP fundraiser with experience raising money for joint fundraising committees said Romney Victory is an efficient way for the Romney campaign to raise money. This method involves one “ask” and one check and avoids bombarding potential donors with multiple contribution requests. This Republican fundraiser said Romney Victory also has been effective at deploying surrogates to headline joint fundraising committee fundraisers, bolstering the campaign’s ability to raise money without reducing the candidate’s time on the stump.

“Not only can Romney Victory control the money, they can do one event and knock everything out,” the fundraiser said. “They’re making it impossible for you not to give.”