The D.C. Democratic Party leadership moved yesterday to unite behind the party's nominees in the November election, including D.C. delegate candidate Eleanor Holmes Norton, whose tax problems have prompted unease and dismay among some activists.

The D.C. Democratic State Committee, the ruling arm of the party, voted overwhelmingly last night to support the party ticket.

Earlier in the day, Norton, mayoral candidate Sharon Pratt Dixon and other members of the ticket met to map out a unified campaign strategy and affirm their support for each other's candidacies, according to Democratic officials.

"The party is going to be working for all of the candidates," said Joslyn M. Williams, chairman of the state committee.

Williams said that as far as the party is concerned, the controversy over Norton's acknowledged failure to file her income-tax returns for seven years is over. "The general consensus is that the issue is now behind us," he said.

But Norton's chief opponent, Republican nominee Harry M. Singleton, continued to try to make hay out of Norton's problems, labeling her an "outsider" in the District because of her failure to vote in several city elections and the failure to file D.C. income-tax returns.

"We cannot afford to send to Congress someone who is an outsider to our community, someone who by the very acts of not voting regularly in our elections and not paying taxes into our treasury has indicated a lack of interest in our affairs," Singleton told several dozen supporters last night at his first fund-raiser for the general election campaign.

Singleton said that if Norton was elected, the tax problem would "be a cloud over her head" that would undermine her ability to lobby Congress for additional revenue for the District.

"Can you imagine the dialogue?" Singleton said to the gathering on the lawn of supporter Bromley Smith in Northwest. " 'Ladies and gentlemen, the federal government must pay its fair share to the District of Columbia.' And the response being, 'Well, madam, have you paid yours?' "

Supporters last night paid $100 each or $150 per couple to sip wine and beer and sample catered dishes as they mingled with Singleton and Louis W. Sullivan, secretary of the Department of Health and Human Services, who spoke briefly on Singleton's behalf.

Jack Sloat, Singleton's finance director, estimated that the fund-raiser netted $15,000 from the crowd, as well as a $5,000 check from the Republican National Committee that Sloat interpreted as a signal that party leaders believe Norton can be defeated, despite a huge Democratic edge in voter registration in the District.

"Before, they didn't think this was winnable," said Sloat.

Norton has also been facing disquiet in her own party over the tax revelations, which first surfaced four days before the Democratic primary last month.

Although Norton won the primary with 40 percent of the vote, she announced afterward that she would pay the city nearly $90,000 in back taxes, penalties and interest.

Most of the concern about her tax problems has been centered in Ward 3, the predominantly white neighborhood west of Rock Creek Park that overwhelmingly supported Norton's opponent in the primary, D.C. Council member Betty Ann Kane (D-At Large).

The leadership of the Ward 3 Democrats voted last month not to give money to Norton's campaign, and some ward leaders, such as council member Jim Nathanson, said they could not yet support Norton.

But at last night's meeting of the Democratic State Committee, representing 70 party activists from around the city, there was no anger publicly expressed toward Norton, and what anger there was seemed more directed at the Ward 3 Democrats.

Elona Evans McNeil, the party's recording secretary, received a big cheer when she reminded party members that they have the right to take away the charter of ward Democratic organizations if they don't support Democratic candidates.

"We can't take for granted the fact that the city always goes for a Democrat . . . . We are running against the Republican National Committee and the White House," she said. "One ward in this city has a misunderstanding about that."

"Whatever your personal feelings are, you support every Democratic candidate," she added.