Virginia Democrats thought incumbent Delegate Dan C. Bowling had a safe seat.

That was before Republican James W. Morefield successfully turned the discussion in their Southwest Virginia coal-producing region into the negative effects of proposed federal cap-and-trade legislation, which would limit companies' carbon emissions.

Now Democrats are fighting to win the race that the political blog Swing State Project has reclassified from "likely Democrat" to a "toss-up."

That story has been repeated across Virginia, as voters awash in weighty national issues have a voice only in state elections this season. Democrats have seen their optimistic hopes of retaking the House of Delegates dim, as the top of their state ticket has fallen further behind in recent polls.

Currently, Republicans hold 53 seats in the House, while Democrats hold 43. Two seats are held by independents, and two are vacant. All 100 seats are up for grabs, but only 69 races are contested.

Republican House Majority Leader H. Morgan Griffith is predicting that Republicans could pick up two seats but added, "If it's a really good Republican night, we do have 12 seats that are close."

His counterpart, Democratic House Minority Leader Ward L. Armstrong, refuses to make predictions but says he is "neither blind nor stupid."

"There are a lot of people who are upset with Washington," Mr. Armstrong said.

"I remind everyone we go to Richmond to enact laws. I take responsibility and we all do for that, but not what the U.S. Congress does. We don't have a say in federal health care reform.

"At the end of the day, a lot of people will differentiate between the two and make a decision to elect a member of the House of Delegates on the candidate's qualifications and views on state issues," Mr. Armstrong said.

A gain of a few delegates would return to Republican hands seats that switched during the Bush presidency.

Among the closely contested races:

In Fairfax County, Bush administration Justice Department official Barbara J. Comstock is trying to knock out one-term Delegate Margaret E. Vanderhye, a Democrat. Each raised and spent more than a half-million dollars as of Oct. 21, according to the Virginia Public Access Project.

Mr. Armstrong said that because of a shift in population, Democrats will eventually win the seats in Fairfax County, where Republican Delegate Thomas D. Rust, a four-term incumbent, is fighting challenger Democrat Stevens R. Miller.

He also thinks Democrats will ultimately take the seat of eight-term incumbent Republican Delegate David B. Albo, who faces Democrat Gregory A. Werkheiser.

Republican businessman Thomas A. "Tag" Greason is challenging two-term incumbent Delegate David E. Poisson in Loudoun County. They've each raised and spent about $300,000.