After sitting out the Democratic primaries, refusing to endorse either Senator Hillary Clinton or Senator Obama, former Vice President Al Gore has heartily endorsed Obama before a packed crowd at the Joe Louis Arena in Detroit calling him "clearly the candidate best able to solve...problems and bring change to America."

Though seemingly unwilling to commit to either candidate during the campaign, perhaps out of respect to the former First Lady, Gore allegedly encouraged Obama in his bid for the presidency and offered some "good political advice" according to the presumptive Democratic nominee.

Former President Clinton strategist and CNN commentator James Carville has called on Senator Barack Obama to draft former Vice President Al Gore as running mate in the upcoming U.S. presidential election.

Appearing on the CNN program, "The Situation Room" hosted by Wolf Blitzer, Carville said selecting Gore would send a message that America was "really serious" about environment and energy issues.

"That would send a signal to the world, to American people, to Congress, to everybody, that America's getting serious about this horrendous problem that we face," he said.

Former Vice President Gore has not ruled out a return to politics though has always indicated he would want to return as president.

The mercurial Carville is highly respected within Democratic party circles for his role as chief  political strategist for the successful presidential campaign of then Arkansas  governor Bill Clinton.

Image: James Carville: Credit:  Office of James Carville