But Republicans continue to blast Space for his vote in favor of a climate-change bill that opponents charge would hurt the eastern Ohio district where coal and coal-generated energy are a big part of the economy.

Independent analysts say Space should still count on a tough race, noting that Democrats face a crucial test in a culturally conservative district that gave GOP presidential candidate John McCain 53 percent of its vote last year.

Patrick Carlisle, a Licking County businessman, said yesterday he is running for the GOP nomination to take on Space and is willing to spend his own money to crank up his campaign.

Failed 2008 primary candidate Jeanette Moll of Zanesville is also a potential challenger, and state Sen. Bob Gibbs, R-Lakeville, said yesterday that he is considering getting into the race.

Space easily won election in 2006, after the fall of disgraced former Rep. Bob Ney, R-Heath, and won a second term in 2008, both good years nationally for Democrats, analysts say.

But the 2010 campaign is shaping up to be much tougher for many Democrats, and even a supposedly second-choice GOP rival could wind up presenting Space with problems next year, analysts say.

"Space has had it easy for the last two cycles in terms of the national environment," said David Wasserman, House editor of the nonpartisan, Washington-based Cook Political Report. "As soon as things turn sour for national Democrats it is possible a 'B' grade or 'C' grade candidate can win and in fact they often do. So Space has to be careful."

Stewart, an Athens Republican, said he decided against running for Congress for family reasons. But he said other potential GOP candidates can defeat Space because his voting record is "out of touch" with the district.

"I think he is incredibly vulnerable," Stewart said.

So does Carlisle, who lives in the Newark area within the 18th District lines and owns Joules Angstrom printing ink company, which has its corporate headquarters in Pataskala and locations in three other states.

Carlisle said he is running and willing to spend "seed" money to get started, because his company is doing well. He wants to contribute to the community and doesn't like Space's actions in Washington, especially the climate-change vote.

Ohio and national Republicans mention Carlisle as a candidate who could give Space a problem.

But Gabby Adler, a Democratic Congressional Campaign Committee spokeswoman, said Space, who has stressed his support for gun rights and a fiscally responsible health-care reform approach, is a good fit with the 18th District.

"Republicans couldn't seal the deal with their No. 1 recruiting target in the 18th because Congressman Space has built a strong base of support in the district through his record of independent leadership," Adler said.

A Space spokesman said the lawmaker is focusing on the pending health-care legislation, not politics, and finding out what his constituents think about proposed reforms during the August recess.

Amy Walter, editor of the nonpartisan politics news service The Hotline, said if Republicans hope to have a big year, Space is a candidate they must beat -- so they will have to consider giving major support to any credible GOP candidate.

But Space, Walter added, remains the favorite, bolstered by his 60 percent winning margin in 2008 and a campaign bankroll of nearly $820,000 as of the end of June.

"Space still has the advantage, " Walter said.

jriskind@dispatch.com