The only place in Washington, D.C., where Republicans still constitute a majority is on K Street.

But as they struggle to stay relevant on Capitol Hill, the heavy-hitting, partisan GOP lobbyists who were so coveted just last year are hitting all the wrong notes.

Newly empowered Democratic aides say many Republican lobbyists are using GOP-approved talking points, dismissing their Members’ substantive concerns and alienating them with hardball political tactics.

“It’s the legacy of the K Street Project,” noted one senior Senate Democratic aide, referring to the GOP-led push over the past decade to create an airtight lock between Republicans on and off the Hill. The project cajoled trade associations and corporate offices into replacing Democrats with Republicans in plum slots downtown, often threatening legislative reprisals if business interests fell out of line.

Democrats insist they are not trying to create a Democratic-leaning K Street Project to bully private interests into hiring their own. Indeed, they blasted the project on the campaign trail as evidence the GOP was too close to its lobbying allies. And Democratic lobbying reform proposals adopted by both chambers this year explicitly ban any similar effort.

Democratic lobbyists said their GOP brethren, slow to recognize the power shift, are stumbling in meetings with the new majority.

“If you haven’t grown up in the Democratic party and you haven’t worked a Democratic staff, you aren’t always sensitive to the right buttons to push,” said Steve Elmendorf, a lobbyist and one-time chief of staff to former House Democratic Leader Richard Gephardt (Mo.), whose young outfit has seen explosive growth thanks to clients eager to build ties to the new leadership.

Several Democratic and Republican lobbyists agreed GOP consultants often get it wrong with Democrats because their corporate pitch is such an easy sell in Republican offices, which already are ideologically sympathetic to businesses’ concerns.

Meeting with Democrats, some Republicans neglect to factor in a much wider array of constituencies that hold sway with the new majority, including labor, environmental and consumer groups.

“Republican lobbyists are used to walking into an office and just saying, ‘I’d like you to do this,’” said one Republican operative who regularly lobbies across the aisle. “With Democrats, you really have to hone your arguments, and you really have to sell them on policy.”

Now that the tables are turned, some Democrats are even questioning whether business clients are being adequately served by their Republican representatives.

They pointed to overt partisans advising business lobbying coalitions. Two senior House Democratic aides who work closely with the business community said trade association members of the Coalition for a Democratic Workplace — which opposed a union-backed bill that would make it easier to organize workers — were ill-served by certain lobbyists hired by the coalition.

The coalition — advised by Navigators, an all-GOP lobbying and consulting shop — ran several ads against vulnerable Democrats for supporting the “card check” bill. The ads, said one of the senior House aides, “really alienated a number of Democrats that would have been willing to work with the business community on other issues.”

In retaliation for the spots, Democrats began calling certain coalition members, such as the American Hospital Association and the National Restaurant Association, and asked them to pressure the coalition to pull the ads.

“My pitch to the business community was, ‘You want a lot from us, but you’re now siding with the hard right,’” said the second senior House Democratic aide. “This card check bill is never going to see the light of day, and this is what you’re going to spend your political capital on?”

Navigators partner Todd Harris dismissed the comment as a “false argument.”

“Whether this bill becomes law in 2007 is irrelevant. The goal of our coalition is to make sure it never becomes law,” he said. He noted that the coalition has run several ads criticizing Republicans who voted for the measure and others praising Democrats who opposed it.

“We don’t set the legislative calendar. The Speaker does. And the Speaker has said this bill is one of her top priorities, the AFL-CIO has said it’s their top priority,” Harris said. “From our perspective, you have to take that very seriously, and therefore we have acted accordingly.”

Spokesmen for both the American Hospital Association and the National Restaurant Association said the people who could respond to inquiries about the card check bill were traveling and not available for comment.

GOP lobbyists also raised the ire of Democratic aides during trade negotiations earlier this year. One high-ranking staffer described a meeting in which “one Republican lobbyist repeatedly interrupted me, saying, basically, Democrats’ concerns were disingenuous and invalid. … It showed a real lack of respect, and it’s not effective for that person’s clients.”

Additionally, Democrats said the National Association of Manufacturers, whose president is former Michigan Gov. John Engler (R), did its member businesses few favors by coming out against part of the trade deal regarding worker protections before it was adopted as part of the bipartisan agreement.

Jay Timmons, NAM’s senior vice president for policy and government relations, said his group has sought to make sure Congressional negotiators understand manufacturers’ concerns as talks go forward. “We have an obligation to do that. Our members expect us to be a voice for them on Capitol Hill. That’s our job,” he said.

Democrats said NAM and other trade associations have nonetheless become more partisan over the past several years under Republican rule.

“We pay attention to their vote scores and their press releases,” said one of the senior House Democratic aides. “If someone appears to be carrying water for the administration, for example, they’re not going to be very effective.”

Meanwhile, several House and Senate Democratic aides complained they repeatedly have been convinced by former Democratic staffers who are now lobbyists to set up meetings for CEOs and business groups, only to find out that the lobbyist who asked for the meeting has been replaced by a higher-ranking GOP lobbyist.

“When they show up, the person who requested the meeting doesn’t, rather, it’s the head of the office who is a fairly partisan member of the opposite party,” one senior Senate Democratic aide said of a recent meeting he had with several industry lobbyists and a CEO.

Democratic aides and lobbyists are quick to note the majority party’s doors are still open to Republicans on the Hill. “I’m happy to see anybody who comes in,” said one senior Senate Democratic aide. “It’s more of an issue of how effective people are going to be.”

Many Democratic party veterans acknowledge that the K Street Project was in fact a logical response from a party newly restored to power after decades in the minority.

“It wasn’t surprising to me when Republicans inserted themselves into all the key jobs in this town — they had the power, and that seemed like an appropriate response,” said lobbyist Patrick Griffin, who ran legislative affairs in the Clinton White House and was a top Senate aide in the 1980s.

But Republicans overstepped when they became “bullies and braggarts,” Griffin said. “Some of these guys thought the K Street Project was their entitlement. In fact, it was just their moment. Now it’s passed, and there’s a new reality.”

As Republican lobbyists struggle to adapt, there are signs that some Democratic staffers are beginning to lose patience.

“At some point in time, if people aren’t getting it, it becomes a waste of time” to meet with Republican lobbyists, said one of the senior House Democratic staffers.

The other senior House Democratic staffer protested that Democrats, who don’t have a reputation for marching in lock step, “couldn’t run a K Street Project if we tried,” while noting that lobbyists already know “that they can’t send Republicans in to see me. I’m not sure if I can trust them, and they’re not sure if they can trust me,” the staffer added.

Scott Parven, who left a bipartisan lobbying shop late last year to help launch an all-Democratic outfit, said Republicans still insist on lobbying Democrats for obvious and understandable reasons.

“They don’t want to give up power in their own offices,” he said.

“But now it’s different. These staffers and Members know who’s who,” he said. “This is a tribal town now. You’re either Red Sox or Yankees.”