For those keeping score -- and apparently there are plenty of Maryland Democratic bigs doing just that -- Doug Duncan took probably about a half-dozen swings at Baltimore Mayor Martin O'Malley yesterday when the Montgomery County executive opened his campaign for governor.

Duncan never mentioned O'Malley by name, and his swipes were artful. You had to listen carefully to hear Duncan dismiss the one-word "Believe" campaign that O'Malley instituted to boost civic pride: "Rhetoric is not a plan. Optimism alone is not a strategy. And you have to do more than just believe things will turn out okay."

And there was this backhanded acknowledgment of O'Malley's star turn at the Democratic National Convention, his selection by Time magazine as one of the nation's five best mayors and the publicity he receives as the strapping, sleeveless leader of his Irish band. "I'm not interested in being seen as a national leader -- I want to make our state a national leader," Duncan said. "I'm not interested in being on stage -- I want to put our state on the national stage."

There were more direct references to Baltimore's problems as well, as Duncan served notice that he did not intend for the Democratic primary to serve as simply a warmup for the poll-leading O'Malley before he takes on Republican Gov. Robert Ehrlich.

Duncan made his official announcement in front of his boyhood home in Rockville, on a cul-de-sac in the kind of neighborhood that doesn't exist in stereotypes of wealthy Montgomery. Ellie Duncan still lives in the house with the enclosed carport where she and her husband raised 13 children -- people in the crowd kept wondering how they all fit. Pumpkins and red, white and yellow balloons tied to the neighbor's chain-link fence gave the whole thing a kind of homespun feel.

Breaking stereotypes about Montgomery will be essential to Duncan's success -- no one from the county has ever been elected governor -- and how the 49-year-old politician goes about it is causing concern. Already, his brusque criticism of O'Malley and some ham-handed e-mails from his campaign -- one criticized O'Malley's band for having a gig on a night "his crime-plagued city lost another life to violence" -- have made people a little nervous.

Senate President Thomas V. Mike Miller is among those concerned that a bitter primary would leave the Democratic nominee bruised and financially busted before taking on the well-financed Ehrlich, who will not face a serious challenger from his own party. "Doug Duncan can't campaign against Baltimore City," Miller says. "He has to take the high road."

In an interview before the announcement, Duncan said he was "baffled" by such advice.

"Look, I'm going to talk about my record and his record, my priorities and his priorities," Duncan said. "I'm not bashing Baltimore. I'm talking about failed leadership in Baltimore. . . . Democrats used to welcome debate; if we don't want debate, no wonder the party's in trouble."

Back in the day, Democrats thought nothing of raucous primaries. Sen. Barbara Mikulski and two-term governors William Donald Schaefer and Parris Glendening each made it through party fights. On the other hand, an early start for Kathleen Kennedy Townsend, and help from party leaders, cleared the path for her to claim the Democratic nomination in 2002. The party lost the governor's mansion for the first time in nearly 40 years. Some feel a competitive primary either would have sharpened her political skills -- or given Democrats a candidate who might have matched up better against Ehrlich.

But University of Maryland professor Paul S. Herrnson says it is a "unique" year for Democrats, as they face a Republican incumbent who will raise, perhaps, tens of millions of dollars.

Rep. Chris Van Hollen, who waged an underdog campaign to defeat Mark Shriver and others in a Democratic primary and then unseated longtime GOP Rep. Constance Morella, said the primary was good for him, because it focused attention on the race and energized Democrats.

And Maryland Democratic Party Chairman Terry Lierman said he is not among those worried that the race will be divisive. He said there could be Democratic primaries for governor, the U.S. Senate, attorney general, comptroller, an open congressional seat and legislative office.

"I personally think primaries are very good: They energize a lot of people; they bring new people into the process; they heighten awareness of the campaign," he said.

Van Hollen, who yesterday endorsed Duncan's campaign, said what was important in his primary was that "all of us focused on the goal of electing a Democrat."

Duncan left little doubt that he wants Ehrlich defeated -- but also that he wants to be the one to do it.