Washington, D.C., superlobbyist Dirk Van Dongen has agreed to serve as D.C. finance chairman for Republican Rudy Giuliani’s nascent 2008 presidential bid, and allies of the former New York mayor say the move is only a preview of the high-profile, inside-the-Beltway support he is building.

Van Dongen, who heads the National Association of Wholesaler-Distributors and is a top Republican fundraiser with close ties to President Bush, represents a big catch for Giuliani among the president’s top money men — the group of “Rangers and Pioneers” who helped pour millions into his two White House campaigns.

It also signals some of the first tangible evidence of the former mayor’s outreach to Washington insiders as he lays the groundwork for a 2008 run. To this point he has been much more low-key in those efforts than Sen. John McCain (Ariz.) and former Massachusetts Gov. Mitt Romney, his top rivals for the GOP nod.

The details of Van Dongen’s role are still in the early stages of being worked out.

In a brief interview, he said that he was pleased to do whatever he could to support Giuliani and he praised the former mayor’s record of leadership in a city that he said many had deemed ungovernable.

“We’re New Yorkers, we actually live in New York City and Washington,” Van Dongen said. “I know what New York City was like prior to his becoming mayor and I know what New York City was like after his two terms as mayor.”

Van Dongen and his wife split their time between New York and Washington. Their daughter, Rachel Van Dongen, is a senior staff writer for Roll Call.

Van Dongen also said he was involved in building support for Giuliani’s abbreviated 2000 Senate bid, which Giuliani ended after being diagnosed with prostate cancer in April of that year.

A source close to the Giuliani campaign said that more endorsements and support from within the Beltway would be forthcoming.

“Meetings have been taking place everywhere from K Street to the Hill,” said the Giuliani source. “You will see in the next few weeks the committee announcing some great supporters who will be helping the mayor’s efforts.”

While Giuliani has obvious ties to the financial powerbrokers on Wall Street, Van Dongen’s willingness to be the former mayor’s fundraising point person here is significant both in Washington circles and in the world of major GOP donors.

There has been fierce behind-the-scenes competition among top White House contenders to land the major players on Bush’s money team. And other donors are watching closely to see where those individuals gravitate.

Van Dongen, Wayne Berman and Ron Kaufman represent three of the biggest Washington, D.C.-based commodities in the group of Bush money men.

Berman, a lobbyist who heads Berman Enterprises, Inc., has signed on with McCain while Kaufman, a senior executive with Dutko Worldwide and a top Bush fundraiser is backing Romney, with whom he shares Massachusetts ties.

Van Dongen and Berman were Rangers for Bush’s 2004 re-election campaign, a status earned by bundling at least $200,000 in contributions. Kaufman was a Bush Pioneer, a distinction given to those who bundled at least $100,000.

Giuliani already has a handful of Bush Pioneers and Rangers on his team but none with the insider stature of Van Dongen.

“This is a fantastic inside the Beltway pickup for Rudy Giuliani,” said one GOP campaign operative who is not aligned with any of the 2008 contenders. “Dirk has helped to raise millions of dollars for Republican candidates and knows where to find the money.”

Van Dongen was heavily involved in then-Sen. George Allen’s (R-Va.) re-election bid in 2006 and also in aiding now-Sen. John Thune’s (R-S.D.) defeat of then-Senate Minority Leader Tom Daschle (D-S.D.) in 2004. Allen was considered a leading White House contender before his defeat by now-Sen. Jim Webb (D-Va.).

On the Hill, GOP Reps. Peter King (N.Y.), Vito Fossella (N.Y.) and Pete Sessions (Texas) are leading Giuliani’s outreach efforts to Members. Rep. Mary Bono (R-Calif.) also announced her support last week.

Guy Harrison, Sessions’ chief of staff, said that at this point the Members are focusing on educating their colleagues about Giuliani’s record of “conservative governance” in New York.

“We’re making sure that our Members understand it’s not just about being America’s Mayor, it’s also about governance that works,” Harrison said.

Giuliani still enjoys wide popularity due to his tenure as mayor during the Sept. 11, 2001, terrorist attacks on the World Trade Center, and early 2008 polls show him in a strong position to win his party’s nomination.

However, winning the nod still appears to be a difficult task for Giuliani, whose moderate social positions are widely thought to be unpalatable for conservative primary voters.

Meanwhile, the Republican presidential field grew by one over the weekend when former Arkansas Gov. Mike Huckabee officially announced his campaign.

Among the other candidates rounding out the GOP’s White House field are Sen. Sam Brownback (Kan.), Rep. Duncan Hunter (Calif.), Rep. Tom Tancredo (Colo.), former Virginia Gov. Jim Gilmore and former Wisconsin Gov. Tommy Thompson.