Yesterday's dispatch declared: "What You Can Believe About Martin O'Malley: Rhetoric vs. Reality." The day before, it was "Martin O'Malley: The Boy in the Band," a blistering flier accusing the Baltimore mayor of "strumming the night away" in his Irish rock group while people were murdered in his "crime-plagued city."

That followed a Top 10 list forwarded to reporters last week that mocked O'Malley for comparing in a television interview his hiring of several police chiefs to Abraham Lincoln's succession of war generals.

In each case, the sender was the campaign of a fellow Democrat, Montgomery County Executive Douglas M. Duncan, who has dramatically ratcheted up his attacks in the days leading to O'Malley's official declaration of his candidacy for governor today.

"Doug's going to run a very aggressive campaign, and we plan to enter into a very vigorous debate on all the issues," said Duncan's campaign's manager, Scott Arceneaux. "That's what inspires what you're seeing."

Whether any of it is helping Duncan -- who plans to make his bid for governor official later this fall -- became a matter of vigorous debate between boosters of the two hopefuls yesterday.

Lanny Davis, a former White House counsel who lives in Montgomery County, said Duncan is "misreading his own electorate" and risks a backlash by going negative so early in the race.

"Duncan is not only hurting himself in Baltimore, where people are just getting to know him, but also in Montgomery County, where people don't like negative politics," said Davis, an O'Malley supporter. "I think it's very risky."

Sen. P. J. Hogan (D-Montgomery), a Duncan supporter, argued that what Duncan is doing is perfectly legitimate, given that O'Malley's announcement will usher in a period of heightened scrutiny of both candidates' records. In his early travels across the state, O'Malley has spoken of a Baltimore "comeback" and touted progress in addressing violent crime, drug addiction and other urban ills.

"If someone is holding up their record, people have a right to question it," Hogan said.

The document released by the Duncan campaign yesterday takes issue with several statements made by O'Malley about the city's progress under his stewardship. At one point, it states that "Baltimore is still plagued by homicides, has the worst-performing schools in the state and the highest property taxes in Maryland."

Several elected officials and business leaders from the city said yesterday that they consider the document a slap in the face.

Del. Maggie L. McIntosh (D-Baltimore) said Duncan's comments reflect "an attitude about the city."

"Whatever we do, we can't measure up to his standards," said McIntosh, an O'Malley supporter. "The communities in Baltimore feel they are making tremendous progress. . . . He will have to walk a long mile to overcome these comments."

O'Malley's campaign manager, Jonathan Epstein, said the attacks could "turn people off. Our campaign isn't focused on name-calling."

Early primary polling has shown O'Malley with a double-digit lead, which many analysts suggested is driving Duncan's attacks.

"Probably the fact that he's trailing in the polls has made him realize he has to pull off the gloves earlier than he would otherwise," said James G. Gimpel, a political science professor at the University of Maryland.

Gimpel said Duncan's criticism could prompt a closer comparison of the two executives' records that would be favorable to Duncan.

Matthew Crenson, a political science professor at Johns Hopkins University in Baltimore, said that Duncan's attacks could undermine his place in the race as "the serious statesmen who has real policy positions."

"His potential was mostly in the projection of maturity," Crenson said, adding that some of the attacks seem juvenile and "may just turn people off."

Crenson said Duncan may also wind up handing Republicans some ammunition to use against O'Malley if the mayor becomes the Democratic nominee.

"They will take advantage of this," he said. "I would imagine many Republicans are going to leap on Duncan's criticisms."

Montgomery County Executive Douglas M. Duncan has been releasing documents attacking Baltimore Mayor Martin O'Malley and his record.