Presidential hopefuls Rick Perry and Mitt Romney have brought their fight for the GOP nomination to K Street, and they will hold back-to-back fundraisers next week aimed at Beltway-area donors.

After months of sitting on the sidelines, the sought-after Washington, D.C., lawyers and lobbyists who’ve helped pull in the big money for past presidential races are finally starting to pick favorites.

The Perry-Romney matchup on K Street mirrors the larger primary contest, with Romney, the former governor of Massachusetts, drawing heavily on ex-aides to and loyalists of President George W. Bush. Perry, the governor of Texas, is leaning in part on his Lone Star State allies and on core conservatives.

The candidates, who are emerging as the GOP primary frontrunners, will hold two Washington-area fundraisers apiece in the coming weeks. Perry’s kickoff events, slated for Tuesday, are being hosted by more than two dozen prominent GOP donors who will give $10,000 apiece. The two events, which will take place at the Willard Hotel and at the home of Mary Ourisman, the former U.S. ambassador to the Barbados and the Eastern Caribbean, could net Perry half a million dollars in one day.

“Perry is not a well-traveled D.C. figure, so these events have a dual purpose,” one GOP organizer said. “Raising money, of course. But also, they are designed to introduce the governor to a broader D.C. community.”

Event hosts include Dirk Van Dongen, president of the National Association of Wholesaler-Distributors, a top bundler for both Bush and Sen. John McCain (Ariz.), the GOP presidential nominee in 2008.

Romney’s two Washington-area fundraisers are scheduled for Sept. 29 and Oct. 25, at the Bethesda North Marriott in Maryland and at the Northern Virginia home of Bobbie and William Kilberg. She’s a former Bush aide who heads the Northern Virginia Technology Council, and he’s a partner with Gibson, Dunn & Crutcher. Another partner at that firm, Howard Adler, is also playing host.

Romney’s bench is heavy with ex-Bush administration officials, including Wayne Berman, a former bundler for both Bush and McCain who was assistant secretary of Commerce for policy and is now chairman of Ogilvy Government Relations. A trio of Bush loyalists from Dutko Grayling is also helping Romney: Ron Kaufman, chairman of the firm’s executive committee and a former top adviser in the Bush White House, and managing partners Brad Card and former Bush aide David Beightol.

“Having Gov. Perry in the race has helped sharpen some people’s minds,” Beightol said. “People who had been sitting on the sidelines are ready to get in now.”

Plenty of big donors and Washington-area bundlers are still sitting out the money chase. As of June 30, more than two-thirds of the 131 bundlers who had raised $100,000 or more for McCain had yet to donate to a presidential contender in 2011, according to an analysis by the Center for Public Integrity. That is starting to change, but many remain undecided.

“I’m not going to get involved,” said Charlie Black, chairman of the Prime Policy Group and a major GOP donor who raised at least $100,000 as a “Pioneer for Bush.” “Maybe in the general election if the nominee asks me to.”

Black said his candidate of choice had been Indiana Gov. Mitch Daniels.

K Street is not the most lucrative place for GOP presidential hopefuls to go looking for bundlers, the well-connected money raisers on whom candidates rely to round up $2,500 checks from dozens of individuals. The big donor states remain California, Florida, New York and Texas — places where both Perry and Romney are also trolling for bundlers and donors.

But D.C. remains an important influence center for both frontrunners, particularly as they angle for endorsements on Capitol Hill.

Perry, who until now has drawn heavily on his home-state connections to raise money, is getting some help from the Texas-on-the-Potomac crowd, including Dennis Stephens, a government affairs counselor for K&L Gates who served on the staffs of former House Majority Leader Dick Armey and Rep. Joe Barton, both Texas Republicans.

Another former Barton aide, Jeffrey M. MacKinnon, now a partner at Ryan, MacKinnon, Vasapoli and Berzok, is helping host one of Perry’s kickoff events. Also on the host committee is Matt Mackowiak, founder and president of the Potomac Strategy Group and a former press secretary for Sen. Kay Bailey Hutchison (R-Texas) who also helped with the Bush campaign.

The struggle between Romney and Perry for the heart of K Street contrasts with other GOP primaries over the past decade, when Bush in 2000 and McCain in 2008 enjoyed extensive Washington, D.C., support from the outset. Romney picked up friends here during his last presidential bid, leaving Perry with the most work to do. As invitations fly around town for the competing Perry and Romney fundraisers, many expect the donor picture to finally come into focus.

“Events like this have a way of moving the decision-making process along,” said Alan C. Sobba, chief policy and communications officer for the International Derivatives Clearing Group, who is on the host committee for one of Perry’s kickoff Washington events. “Some people support both candidates. So what these things tend to do is start to force people to make a decision.”