Dan Lucas, the hard-charging campaign manager for Rep. James P. Moran Jr. (D-Va.), has resigned from the post after a year of steering the politician's run for an eighth term in Congress.

Lucas, who was brought in to manage Moran's campaign in July 2003, when it looked as if the embattled representative would face a tough Democratic field for his seat in the June 8 primary, submitted his resignation early last week, according to several Moran advisers. They said Lucas was brought in largely to get Moran through his primary challenge, the first since he was elected in 1990.

"All along, Dan had thought he would only work with Jim through the primary, and he was gracious enough to stay through the convention," said Mame Reiley, an adviser who has run several of Moran's campaigns.

Others said that because Lucas had gotten Moran through a potentially difficult period in his political career, it was time for him to move on to new challenges.

Lucas helped Sen. Hillary Rodham Clinton (D-N.Y.) win her senatorial bid in 2000 and worked on presidential hopeful Bill Bradley's Democratic primary campaign in Iowa. When Lucas was hired, Moran expected to face former Fairfax County Board of Supervisors chairman Katherine K. Hanley and Arlington County Board member Jay Fisette in the primary. Many politicians considered Moran vulnerable following controversies over his personal finances and an uproar over a comment he made at a peace vigil in Reston that American Jews were pushing the country toward war with Iraq.

"This is a different phase of the campaign we're entering now," said Michael Brown, who stepped in to replace Lucas on Monday. Brown has worked with the congressman off and on since 1990.

"Jim had never had a primary challenge before," Brown said. "Now the competition has shifted."

Both Hanley and Fisette dropped out, and Moran defeated Andrew Rosenberg, an Alexandria lawyer, 59 percent to 41 percent.

Moran and Lucas did not return phone calls to their cell phones Tuesday.

Several sources close to the congressman, who spoke on condition that they not be named, said that Moran and several advisers became frustrated with Lucas's style, which some felt didn't mesh with that of Moran's close-knit group of advisers.

Several said that Moran became furious at Lucas over what they described as a heated exchange with several Moran detractors on a campaign Web site message board.

"There were some bumps in the road that they just couldn't get over," said one source.

Lucas's resignation is the second defection from Moran's camp in several months. In June, just four days before the party primary, Alan Secrest, an Alexandria-based pollster, resigned from Moran's campaign and said the congressman had made an anti-Semitic reference during a private meeting with advisers.

Moran and others who were in the room with Secrest vehemently denied that Moran had made any such comment, and Secrest refused to elaborate.

Moran staffers said that they were focused on the general election against Republican Lisa Marie Cheney and that Lucas's resignation was not a sign that Moran was changing course or that his campaign was in trouble.

"We're concentrating on November 2," said Dan Steen, a longtime Moran friend and campaign director. "Dan served Jim well, and we're all focused on making sure that he can win in November."

Dan Lucas ran Moran's campaign for a year, through the primary.