From CBS News’ John Bentley:

ABOARD THE STRAIGHT TALK EXPRESS – “Cut him loose,” was John McCain’s advice today to Barack Obama after Gen. Wesley Clark refused to back down from comments critical of McCain’s leadership. “I think it’s up to Sen. Obama now to not only repudiate him, but to cut him loose.”

Gen. Clark said yesterday that McCain getting shot down over Vietnam wasn’t “a qualification to be president.” Clark reiterated today that he respected McCain’s service, but that it wouldn’t make him a good commander-in-chief. “He not only supported going into a war we didn't have to fight in Iraq, but has time and again undervalued other, non-military elements of national power that must be used effectively to protect America,” Clark said. “As an American and former military officer, I will not back down if I believe someone doesn't have sound judgment when it comes to our nation's most critical issues."

McCain made the comments in the inaugural press conference aboard his new flying Straight Talk Express on the way to Cartagena, Colombia, in support of the Colombian Free Trade Agreement. Obama has opposed the agreement, citing labor and environmental issues in Colombia. In addition to the advice about Clark, McCain also offered a history lesson to his opponent. “He’s a protectionist and anti-free trade,” McCain said about Obama. “The overwhelming majority of historians will tell you that protectionism and isolationism were a major factor in one of the greatest depressions in the modern history of this country.”