Martin O'Malley, the former Maryland governor who is considering a presidential campaign, said Sunday that voters shouldn't coronate Hillary Clinton as the Democratic nominee -- arguing in a national television appearance that the nation needs new leadership.

In some of his strongest criticism of the presumed front runner for the nomination, O'Malley said that Clinton was the best candidate "for those times" when he endorsed her campaign in 2008 against then-Senator Barack Obama.


O'Malley stressed he believed that was true "for those times."

"I believe that new perspectives and new leadership is needed," O'Malley said on ABC's "This Week."

"Let's be honest here, the presidency of the United States is not some crown to be passed between two families," he added. "It is an awesome and sacred trust that [is] to be earned and exercised on behalf of the American people."

O'Malley never spoke Clinton's name, but when program host George Stephanopoulos asked whether Clinton was a candidate who could take on "special interests," the former governor said he doesn't know.

"I don't know where she stands," O'Malley said. "Will she represent a break with the failed policies of the past? Well, I don't know."

O'Malley must walk a difficult line in his approach to Clinton, a long-time ally. Criticizing the former Secretary of State too directly could backfire, particularly if polls showing her dominance of the 2016 field prove true. On the other hand, he needs to draw distinctions with the front runner to be taken seriously as a potential candidate.

In recent weeks he has become more aggressive, jabbing at the politics of "triangulation" that allowed former President Bill Clinton to work with a Republican-controlled Congress.

O'Malley has also recently called for tougher Wall Street regulations in an effort to court the more progressive wing of the party.

O'Malley, whose second term as governor ended in January, reiterated that he will make a decision about whether to seek the Democratic nomination this spring. In the meantime, he has been a regular visitor to early primary states. He will return to New Hampshire on Tuesday and will be back in Iowa on April 10.

ABC began the segment playing a scene from the HBO series The Wire that included Thomas "Tommy" Carcetti, the fictional mayor of Baltimore that many believe is loosely based on O'Malley. The former governor has been critical of the popular program and has had an uneasy relationship with show creator David Simon.