Virginia Republican Gov. Bob McDonnell is outpacing Democratic Gov. Martin O'Malley of Maryland in the fundraising battle that will underwrite the Potomac River rivals' fight this November over nearly a dozen governorships.

The Republican Governors Association, headed by McDonnell, took in $16.7 million between April 1 and June 30 -- nearly double what the group brought in during the same period in 2008, it said. Meanwhile, the Democratic Governors Association under O'Malley's stewardship raised $13 million, about $7.5 million more than 2008, though that includes money from the DGA's politically affiliated nonprofit groups.

The RGA does not have to disclose how much its affiliated groups rake in until 2013, and it does not plan to do so.

In the first six months of 2012, the RGA has raised $29 million while the DGA raised $21 million.

McDonnell and O'Malley both shattered fundraising totals as they rack up the cash needed to compete in 11 governors races in November, including New Hampshire, North Carolina and Indiana. Republicans currently control 29 governorships while Democrats hold 20. Rhode Island Gov. Lincoln Chafee is an independent.

"With record resources and a favorable political map that includes critical battleground states and many pickup opportunities, the RGA is prepared to make a major impact on this year's elections and expand our majority," McDonnell said.

McDonnell credited last month's Wisconsin gubernatorial recall election with helping boost the committee's war chest and rally the Republican base at a time when attention is traditionally focused on presidential politics. But that race was also expensive for the RGA, which spent nearly $9 million to help Gov. Scott Walker hold his seat in an important swing state.

Still, it was a win for the RGA, and the first chance for McDonnell to test his political operation before the fall elections. The DGA spent about $3.5 million in Wisconsin, funneled largely to local political groups working to elect Democrat Tom Barrett.

Both organizations declined to say how much cash they now have on hand until reports are posted publicly later this month.

As the political fight between the governors groups heats up, so have exchanges between McDonnell and O'Malley.

McDonnell's RGA painted O'Malley as a tax-and-spend liberal in a web video posted during the Wisconsin race.

Last week, O'Malley slammed McDonnell after the Supreme Court upheld President Obama's health care law, invoking an ultrasound-before-abortion bill that the Virginia General Assembly passed earlier this year.

"The only health care mandate they can embrace," O'Malley said of Republicans, "are transvaginal probes for women."