Katherine K. Hanley, the Board of Supervisors chairman in Fairfax County, said yesterday that she is exploring a run for Congress next year in Virginia's 8th District, making her the second elected Democrat to express interest in challenging Rep. James P. Moran Jr. in the party primary.

"People have asked me to look at running for Congress," said Hanley, a former schoolteacher and a veteran of Fairfax politics, who is finishing her second full, four-year term as the county's top elected official. "I am exploring my opportunities."

Hanley, 60, emerged as a possible Democratic challenger during the political fallout from Moran's suggestion at a recent antiwar forum in Reston that Jews were pushing the nation into war with Iraq. Her entry into the race could intensify a fight among Democrats eager to oust Moran from his strongly Democratic district. It also would set off a succession battle for the board chairman's job.

On Wednesday, state Sen. Leslie L. Byrne (Fairfax), a former member of Congress, said she might challenge Moran for the Democratic nomination. Other Northern Virginia Democrats are said to be considering taking on the seven-term incumbent from Alexandria.

Moran has apologized for his remarks, but the furor has continued, in part because he has been embroiled in controversies before over possible conflicts of interest and other ethical issues.

Hanley lives in Reston, which became part of the 8th District two years ago because of redistricting.

A run for Congress could complicate Hanley's plans to run for reelection this year to another term on the county board. When asked whether she would give up that campaign, she said, "Let's not get ahead of ourselves." But she acknowledged that running for her county job in a hotly contested election, taking office in January and then announcing a campaign for Congress would present "a lot of complications."

Meanwhile, Moran's support among congressional Democrats faltered yesterday as his aides tried to contain the criticism over his March 3 remarks that the nation would not be heading into a war with Iraq if not for the Jewish community.

Moran, through a spokesman, said yesterday that he has "every intention" of running for an eighth term in 2004. But some veteran Democrats in Congress backed away from Moran.

"I think he's done a lot of damage to himself, not just with his statement but with . . . a series of actions," said Rep. Henry A. Waxman (D-Calif.). "I will not support him, and I hope the Democratic Party will not support him."

In Fairfax, Democrats and some Republicans said yesterday that Hanley could carry off both campaigns. They pointed out that Thomas M. Davis III (R) ran successfully for the U.S. House in 1994, three years into his first term as Board of Supervisors chairman. Davis's going to Congress led to Hanley's winning the job of board chairman in a February 1995 special election.

"I don't think people will necessarily hold ambition against a politician," said Supervisor Michael R. Frey (R-Sully), who said he would consider running to succeed Hanley as board chairman. "The danger would be if she looked beyond the election for board chairman as she campaigned."

Two Republicans, School Board member Mychele B. Brickner (At Large) and former Board of Supervisors chairman John F. "Jack" Herrity, are battling for the right to face Hanley in November, the first contested primary race for board chairman in 12 years.

Brickner declined to comment yesterday on Hanley's plans.

But other Republicans said Hanley would do herself political damage by juggling both campaigns.

John T. "Til" Hazel Jr., a prominent developer and Herrity ally, said Herrity would use Hanley's interest in the Moran seat against her. "I think that's a high-risk proposition if Hanley tries to do both. But she may very well try to do it," Hazel said. "Herrity . . . would make life uncomfortable for her."

Hanley said a "broad group'' of supporters has encouraged her to run for Moran's seat, particularly as he has appeared more vulnerable in recent days.

"Her grasp of almost any topic concerning county government, be it the budget or sewers, is incredible," said Sophie R. Hoffman, president of the Jewish Community Council of Greater Washington, which has condemned Moran's comments. "She does what she does effectively, but almost quietly."

The redrawn 8th District still includes Moran's political base in Alexandria and Arlington, but it has been extended to the west, shifting more of the district's political clout to Fairfax County, where Hanley is popular with traditional Democratic constituencies.

Hanley also has courted Fairfax's powerful business and development interests. That alliance suffered a setback in November when voters defeated a proposed sales tax increase for transportation projects. Hanley led the county supervisors in an endorsement early in the campaign.

She is one of 10 supervisors. Nine are elected by district. The chairman is elected countywide.

In two elections for board chairman, she has had a virtually free ride from Fairfax Republicans, who have failed to field serious candidates. She has not been a prodigious fundraiser, and she entered this election season with less money in the bank than several other supervisors: just over $50,000 in December, according to campaign finance reports.

Besides Byrne, a Democratic field in the 8th District could include state Sen. Janet D. Howell (Fairfax), Del. Kenneth R. Plum (Fairfax), former lieutenant governor Donald S. Beyer Jr., Alexandria Mayor Kerry J. Donley and Fairfax Supervisor Gerald E. Connolly (D-Providence). Connolly also would be a possible successor to Hanley as board chairman.

Staff writers Michael D. Shear and Juliet Eilperin contributed to this report.

Katherine K. Hanley's decision is complicated by her running for reelection this year in Fairfax.Rep. James P. Moran Jr.'s troubles continue to attract potential Democratic challengers.