TAMPA, Fla. -- Working to preempt a parade of Republican governors who will take the stage tonight at their party's national convention, Maryland Gov. Martin O'Malley said here that the GOP vision for the nation's economy would "spell disaster for America's middle class" and that soon-to-be nominee Mitt Romney "doesn't have what it takes to grow this economy."

O'Malley, who chairs the Democratic Governors Association, arrived in Tampa on Monday for a bevy of television and radio interviews in an attempt to counter the message voters will hear from Republicans over the next three days. The effort, which comes as O'Malley is preparing for a prominent speaking role at the Democratic convention in Charlotte next week, has continued to fuel speculation about his own national political ambitions in 2016.

"The lessons [Romney] learned as a corporate buyout specialist were not lessons that should be applied to a national economy," said O'Malley, who was joined by Obama campaign adviser Robert Gibbs and Los Angeles Mayor Antonio Villaraigosa at a press conference focused on Romney's time leading Bain Capital. "In this economy there are ship builders and there are ship wreckers."

Maryland Republicans attending the convention, many of whom are state lawmakers, held an impromptu press conference to dispute O'Malley's claims. State House Minority Leader Anthony J. O'Donnell said he thought the governor's appearance in Tampa lowered the civility of state politics and threatened that, in response, Maryland lawmakers might just show up to crash the Democratic convention next week.

"This governor has raised taxes excessively on Marylanders, has lost jobs at a higher rate than any other state in the nation," O'Donnell said. "For him to come down here to criticize our leaders at our convention is very troubling to us."

After suspending the convention Monday as Tropical Storm Isaac threatened Florida's coast, Republicans are getting things started today. Several state executives, including Virginia Gov. Bob McDonnell -- O'Malley's counterweight at the Republican Governors Association -- and Wisconsin Gov. Scott Walker will address delegates tonight. New Jersey Gov. Chris Christie will offer the keynote address.

O'Malley, who returns to Maryland today, took swipes at several of them, arguing that the party's economic vision has not translated into job creation in the states and therefore would not work for the nation.

"Tonight you're going to see Chris Christie, a governor who has the fourth-worst unemployment rate of any state in the nation, deliver his angry, Don Rickles keynote, extolling the virtues of their candidate, Gov. Romney, who had one of the worst rates of job creation," O'Malley said.

Republicans, of course, are also eager to discuss the economy. A Washington Post/ABC News poll this week showed that seven in 10 registered voters considered Obama's handling of the economy a significant factor in this election. That same poll found that 54 percent of respondents disapproved of the president's efforts.

On the race itself, the candidates were about even, with 47 percent backing Romney and 46 percent supporting Obama.

"President Obama and his advisers have a clear message for Americans struggling in the Obama economy: it could be worse," Romney campaign spokeswoman Andrea Saul said in a statement. "But with half of recent college graduates unemployed or underemployed and consumer confidence plummeting to a nine-month low, it's clear that things can't get much worse for middle-class families."