Montgomery County Executive Douglas M. Duncan (D) collected a fall harvest's worth of local endorsements yesterday in his bid for governor, aiming to strengthen support at home and prove to voters elsewhere in Maryland that he is backed by those who know him best.

More than 50 current and former elected officials, including virtually every incumbent in Montgomery, rallied on the steps of a county office building in Rockville to announce that they support Duncan over his opponent for the Democratic nomination, Baltimore Mayor Martin J. O'Malley.

The backers include all but five members of the county's 32-member delegation to the General Assembly, five of nine County Council members, two congressmen and several mayors and council members from Montgomery's larger municipalities.

"This guy is a natural," said former representative Michael Barnes (D-Md.). "He was born to be a great government executive. He makes things happen."

Barnes and others praised Duncan for spending on public education, improving access to health care, pushing for new roads and mass transit and protecting natural resources.

"People in this state and around the country are hungry for a no-nonsense leader focused on results, not rhetoric," said Rep. Chris Van Hollen (D-Md.), who joined Rep. Albert R. Wynn (D-Md.) in backing Duncan.

Endorsements, however, don't necessarily translate into votes. Although few expect O'Malley to win Montgomery, there are signs that Duncan may need to shore up his support at home to win statewide.

Earlier this month, a poll published in the Baltimore Sun showed Duncan with 37 percent of the vote in Montgomery, compared with O'Malley's 20 percent. Duncan campaign officials discount the poll, saying it included an unusually small sample.

Some elected officials say Duncan's support in the county may be undercut because of concern about poorly managed growth.

"O'Malley will get a lot of votes here largely because of concerns about how cozy Doug Duncan is with the development industry," said council member Phil Andrews (D-Gaithersburg-Rockville), a frequent Duncan critic who is staying neutral in the race.

Other residents are upset with Duncan's support for several road projects, including the proposed intercounty connector and the Montrose Parkway, whose construction is underway.

But Duncan backers say they expect residents to look at his overall record -- which includes the revitalization of Silver Spring, reduction of class sizes in schools and the emergence of the local biotechnology industry -- before they cast a vote on a single issue.

"I don't think people here are single-issue voters," said Del. Adrienne A. Mandel (D-Montgomery), who endorsed Duncan yesterday even though she disagrees with him on the intercounty connector.

Duncan's success at winning endorsements from most of the county's elected Democratic establishment, which follows months of phone calls and personal appeals, stands in sharp contrast to his effort in four years ago.

He backed away from the 2002 governor's race when it became clear that most elected officials in Montgomery were supporting then-Lt. Gov. Kathleen Kennedy Townsend (D).

Yesterday's testimonials also highlight his desire to build an impenetrable base of support in Montgomery, home to about 16 percent of the state's registered Democrats.

To offset O'Malley's expected advantage in the Baltimore region, Duncan and his advisers have said they need at least 60 percent of the vote and a large turnout in Montgomery.

O'Malley has signaled that he plans an aggressive campaign in Montgomery. His campaign already does weekly literature distributions in the county and has coordinators in seven of the eight legislative districts.

O'Malley, who grew up in Rockville, has emphasized his local roots in presenting himself as a candidate well versed in Montgomery's needs.

"We are tremendously encouraged by the endorsements that we have received from labor and elected officials across the entire state," said Jonathan Epstein, O'Malley's campaign manager.

Campaign worker Adam Goldberg waves a sign for Douglas Duncan, who was endorsed by more than 50 current and former elected officials in his bid for Maryland governor.