Soon after House GOP leaders released a draft this month of their legislation to reshape the intelligence community, the union representing the Department of Homeland Security discovered language it did not like: The bill gave the president power to exclude the agency's employees from union representation.

Within two days, Rep. Thomas M. Davis III (R-Va.) had stripped the anti-union provisions from the bill. After debate in the House Government Reform Committee that he heads, the revised legislation sailed to the House floor and was approved by Congress this month -- with bargaining rights for thousands of federal workers intact.

The move to placate the National Treasury Employees Union, not a traditional Republican constituency, was a political necessity for Davis, whose Northern Virginia district is home to many white-collar government workers. As he runs for reelection to a sixth term facing scrutiny from a little-known Democratic opponent, the popular congressman is busy doing what he says he loves best: delivering for his constituents in the 11th District.

Only this year Davis has traded the perch of the national GOP fundraising committee he led for four years for one less visible to most Americans but in other ways just as powerful: the committee that oversees the operations of the federal government.

"I like these issues," Davis, 55, said in a recent interview in his Capitol Hill office before testifying on the intelligence bill on the House floor. "I understand them: The [Government Reform] committee is not powerful if you're from Alaska or Rhode Island. But it's powerful if you're from here, from this region."

Davis's opponent in Tuesday's election, retired Foreign Service officer Ken Longmyer, accuses him of cultivating a moderate image that belies votes and alliances with the House's conservative leadership. This week, the Longmyer campaign said Davis was one of nine congressmen to host a reception on Capitol Hill this year for the Rev. Sun Myung Moon. Davis campaign manager John Gibson said Davis did not attend the event or authorize his name to be used as a sponsor. "It's ridiculous to try and associate the congressman with the reverend," Gibson said.

Longmyer also has suggested that the congressman, who began his political career as a supervisor and board chairman in Fairfax County, leans too heavily on his local ties.

Davis, who lives in Vienna, points proudly to his efforts to take care of his home base of central Fairfax and western Prince William counties.

He points to millions of dollars in federal money he has secured for transportation projects in his district to pay for the widening of Route 123 and an engineering study to extend the Orange Line to Reston. At the same time, he says he has helped play a role in setting the GOP's national agenda by supporting President Bush's tax cuts and the war in Iraq.

But Davis is quick to note that he has broken with the administration on several high-profile issues, including limits on stem-cell research (Davis favors more research); oil drilling in the Arctic National Wildlife Refuge (he voted against it) and the expiration of the assault weapons ban (he supported the original ban).

Davis had $1.1 million on hand as of the last campaign finance filing, at the end of September, and Longmyer had $2,500.

As a majority-party congressman in charge of the House's largest committee, Davis has the power to act as a check and balance on the administration.

Or he can thwart the kind of scrutiny sought by the committee's ranking minority member, Rep. Henry A. Waxman (Calif.). While Waxman and other Democrats have complained that Davis has used the committee for partisan purposes -- by refusing to hold hearings on the leak of Valerie Plame's identity as a CIA agent, for example -- Waxman said Davis has worked with Democrats on some issues.

For example, Davis agreed to schedule hearings on the performance of Halliburton, Vice President Cheney's former employer, in its no-bid contract for Iraq reconstruction.

"We had everybody asking us not to hold hearings," Davis said. "But we let whistle-blowers testify as a courtesy for the minority."

A bill to overhaul the U.S. Postal Service passed the committee unanimously, although the administration opposes language transferring some costs to the federal government. Davis also forced a successful roll call vote in the House on a 3.5 percent pay raise for civilian federal workers, over administration objections.

"In terms of oversight and other investigations, he's been considerate of some of the things we wanted to pursue," Waxman said. He added: "That doesn't mean we haven't had our disagreements."

Some legislation Davis pushed through the committee has been more controversial. He authored a bill that loosened policies for contractors to get federal business, a nod to the many defense and information technology firms in his district.

Some politicians and observers of government operations contend that he may have bent over backward for contractors at taxpayers' expense.

"He's unabashedly an advocate for contractors' interests," said Danielle Brian, executive director of the Project on Government Oversight, a watchdog group. "But in doing that, he's reduced transparency in contracting, with less competition."

Davis also supported another bill, pushed by the administration, that denies grievance rights to approximately 700,000 civilian Defense Department workers.

Davis declined to discuss his future, although he has long been said to be eyeing a run for U.S. Senate when Sen. John W. Warner (R-Va.), 77, retires. Warner's term is up in 2008.

As Davis builds alliances that could be helpful in a statewide campaign, he is paying close attention to the heavy concentration of federal workers and contracts across the state, in such places as Virginia Beach.

And he won points with conservatives this year on a key issue in the District, teaming up with D.C. Mayor Anthony A. Williams (D) to launch a federal school voucher program.