For years, opponents have charged that Rep. Richard Gephardt (D-Mo.) is too close to organized labor. Now, he’ll be literally just a few blocks away after opening his presidential campaign office last week in the heart of downtown Washington’s Big Labor neighborhood.

Aides noted that Gephardt’s new headquarters, in an office building at 1620 L St. NW, is four blocks away from his ultimate destination, the White House. But more importantly in the short term, it lands him just a few blocks from the headquarters of the largest labor unions in the nation, including the AFL-CIO.

Gephardt’s new digs opened as other presidential contenders who count Congress as their day job continued to staff up and consolidate their work forces, predominantly on Capitol Hill. The large number of Members of Congress tossing their hats in the ring has had the side effect of putting three of the top campaign operations within three blocks of each other, two of them just four floors apart in the same building. Several more District-based operations could be on the way, depending on what potential candidates decide in the weeks and months ahead.

Sens. Joe Lieberman (D-Conn.) and John Edwards (D-N.C.) converted the offices of their respective leadership political action committees into presidential headquarters, with both operating out of the same office building, Congressional House, at 236 Massachusetts Ave. NE, next door to the Heritage Foundation. Lieberman has a second-floor suite; Edwards a sixth-floor spot, leaving room for some practical jokes about Watergate-esque shenanigans.

“We listen through the vents all the time,” quipped Jano Cabrera, Lieberman’s spokesman.

A couple of blocks away, at 519 C St. NE, Sen. John Kerry (D-Mass.) last month opened the roomiest presidential outpost in the District, renting a three-story townhouse on Stanton Park with more than 7,000 square feet.

Lieberman, Edwards and Kerry have shied away from actually calling their District-based offices their national headquarters, emphasizing that their operations are formally based in their respective home states. Each of the campaigns’ top staffers, however, are working from the Capitol Hill headquarters, although some are likely to eventually head out to the home states.

Privately, aides in each of the camps admit there is a hesitancy to say they work at a District-based headquarters for fear of being tagged with the dreaded label of “Beltway insiders,” particularly with several non-Congressional candidates now in the race. (Receptionists in Kerry’s legislative suite in the Russell Senate Office Building will not give out the number for his headquarters five blocks from the Capitol and instead refer callers to his Boston campaign office.)

However, Steve Elmendorf, Gephardt’s top strategist, said Friday the new downtown office would be the Missouri lawmaker’s “national headquarters” and that there would be several satellite offices, including one in St. Louis. Elmendorf said the St. Louis office wouldn’t be short-changed, particularly since it will serve as the main office for Gephardt’s work in the Missouri primary — which has moved up to early February and is an absolute must-win state for the former Minority Leader.

The acknowledgment that he will be working out of a Washington campaign headquarters goes along with Gephardt’s emerging strategy to embrace his Congressional experience as a sign of strength in a time of global uncertainty. At Friday’s meeting of Democratic National Committee members, Gephardt said his “values and ideas” would trump President Bush’s in 2004, noting that his values were brewed in his Midwest heritage and his ideas came from 27 years in Congress.

Erik Smith, Gephardt’s campaign spokesman, said the headquarters occupied about a quarter of one floor in the office building. At this point, Gephardt has between 30 and 35 people on the campaign staff in offices in the District, St. Louis, Iowa and New Hampshire, with the top advisers in Washington.

That will make it a short hop for Team Gephardt to woo the top labor leaders, whose support the Missouri lawmaker will need to prevail in the increasingly crowded primary.

The headquarters is four blocks from the AFL-CIO building, three blocks from the Service Employees International Union and around the corner from the American Federation of State, County and Municipal Employees.

Elmendorf took a veiled poke at the Kerry campaign’s purportedly pricey D.C. headquarters, declining to say precisely how much Gephardt’s new office was costing. “Less than some other campaigns I hear about,” he joked.

He stressed his campaign’s modus operandi has been to keep overhead costs as low as possible to preserve dollars for critical advertisements and get-out-the-vote operations in early primary states.

Kerry’s campaign has declined to say how much the rent is for their townhouse, although the real estate agent told Roll Call last month that it carried a one-year lease with a series of additional three-month options depending on how the campaign goes.

Prior to moving into his new and larger office, Gephardt had a small fundraising spot downtown that he used for his House campaign committee, costing him $4,015 a month, according to Federal Election Commission records. Edwards and Lieberman should be paying about the same this year for their presidential offices as they paid last year in rent for their leadership PACs, which doled out $2,700 a month for their Congressional House offices.

More District-based presidential operations could be on the way. Sen. Bob Graham (D-Fla.) is expected to open his presidential campaign later next month, and Sens. Chris Dodd (D-Conn.) and Joe Biden (D-Del.) are still contemplating bids.

Rep. Dennis Kucinich (D-Ohio) filed his papers for a presidential campaign last week, but is just beginning to build his infrastructure. His old Congressional campaign office in Cleveland has been converted into a presidential headquarters, but it has virtually no paid staff for now.

“It’s a lot of volunteers right now, but staffing decisions will be made in the weeks to come,” said Doug Gordon, Kucinich’s Congressional press secretary. A decision on whether to open a District office is also a few weeks away.

Despite the close quarters of the top campaign staffs and the candidates’ shoulder-to-shoulder dealings in Congress, Lieberman guessed that the heated nature of the coming campaign won’t spill over into personal bad blood. At least not in Washington.

“I don’t think it’s a problem at all. I’m an optimist about it,” he said. “We’ll fight in the primary states.”