Gov. Martin O'Malley told a national television audience this morning that Republican Gov. Chris Christie would provide "tremendous entertainment value" if he runs for president, but will offer little in the way of "effective government."

O'Malley, a Democrat, appeared for on CBS's Face the Nation opposite GOP Gov. Haley Barbour of Mississippi in a segment that focused on widespread speculation that Christie will jump into the Republican primary battle.

Maryland's governor has been picking on Christie for about a year, starting last January when he blasted the New Jersey governor's attitude toward state workers.

O'Malley has sought to raise his national profile this year, taking on a leadership role in the Democratic Governors Association, making frequent trips to Washington, D.C. and appearing on Sunday talk shows. O'Malley is set to be in North Carolina early next week raising money for the DGA.

On Face the Nation this morning, host Bob Schieffer pressed both his guests on whether Christie's weight should disqualify him from occupying the Oval Office.

Barbour spoke of his own struggles shedding extra pounds, and paid O'Malley a compliment: "You see somebody like me opposed to somebody like Martin [O'Malley], he gets the first swing" because he looks better on television. 

Schieffer next turned to O'Malley, introducing him as the "slim, trim governor of Maryland." O'Malley dodged the Christie weight question, and when chided for doing so by Shieffer, O'Malley said "it was not an evasion, it was a redirection."

O'Malley took some time to criticize the current crop of Republican presidential hopefuls by saying they are "pandering" to the tea party. He noted that Obama "will not be running against the almighty, he'll be running against the alternative" and said the GOP bench might be "deep in personality" but "the pool of ideas is shallow."

Barbour took some shots at Obama, saying the president is going to "have to learn how to lead, or he's going back to Chicago."

Earlier in the segment, U.S. Sen. John McCain, said that Christie would be a "viable candidate" if he runs. But, the 2008 GOP nominee for president did have a warning for New Jersey's governor, saying: "The swimming pool looks a lot better until you jump in."