Nathan Harrington has a problem in his Congress Heights neighborhood: There are too many vacant houses holding down property values and attracting crime, he says, and the city isn’t doing enough to fix the problem.

So on Thursday, the 31-year-old teacher decided to seek action in the halls of power. But the halls he chose were not in D.C.’s city hall, the John A. Wilson Building, or in the Southwest offices of city property regulators, but in the Longworth House Office Building.

Harrington took his grievances to Rep. Andy Harris (R-Md.), the congressman who moved successfully last month to attach a provision to the District budget that would block the city’s new marijuana decriminalization law and later defended his move by saying in a radio interview that, for D.C. residents, “Congress is their local legislature.”

Harrington joined more than two dozen protesters who descended on Harris’s Capitol Hill office Thursday for a tongue-in-cheek “constituent service day” meant more to highlight Harris’s intervention in local affairs than their own frustrations with District government services.

“Either he represents us, or he doesn’t,” Harrington said. “Either he cares about what happens in the city, or he doesn’t.”

Harris did not appear to hear the protesters’ complaints personally, but his chief of staff, Kevin C. Reigrut, stood in the office’s waiting room for an hour as activists filed in and out to register their complaints.

“I think there’s a lot of street signs that could be more visible,” said Rachelle Yeung, a 26-year-old legislative analyst for the Marijuana Policy Project.

“More bike lanes,” added colleague Lauren Padgett, also 26.

Reigrut politely accepted the protesters’ entreaties, occasionally indulging in a debate over the scope of Article 1, Section 8 of the Constitution, which grants Congress complete authority over District affairs.

“It’s been a very good exercise in peaceable assembly,” he said of the protest.

The civility of the protest was briefly thrown into question when Adam Eidinger, a leader of the pending effort to legalize marijuana in the District through a ballot initiative, suggested to Reigrut that congressional meddling in city affairs would lead to widespread civil disobedience and possible “terrorist groups” seeking greater D.C. autonomy.

“I would suggest you tone that rhetoric down,” Reigrut told him.

Back in the hall, Eidinger defended his statements but said, “Just to clarify this, I would never form a terrorist organization.”

The protest was organized by D.C. Vote, the nonprofit voting-rights advocacy group. Executive Director Kim Perry said she has visited Harris’s office every day for three weeks seeking a meeting with the congressman, following up her visits with daily e-mails, but has not been able to schedule a sit-down.

“Every day there’s a different excuse,” she said. “But we’re not going away. You can only ignore us for so long.”

Other District residents have had better luck getting a meeting: A group of African American Republicans met Wednesday with a Harris aide, said Ralph J. Chittams Sr., a vice chairman of the D.C. Republican Party.

Chittams said the meeting ended with the parties agreeing to disagree about Harris’s amendment, which is part of a spending bill that has passed the House but remains subject to negotiations with Senate Democrats.

“We’re not impugning his motives,” he said. “Our problem was, as congressman from the 1st Congressional District of Maryland, he had no business butting into a local matter.”

Chittams was more critical of Thursday’s protesters, who did not secure an invitation for a meeting, as his group had. “That’s how Republicans do things, decently and in order,” he said. “We don’t just bum rush an office.”