A little post-debate analysis is in order.  First off we have Ron Paul (R-TX) pointing out the obvious to Mitt Romney (R-MA) regarding the Constitution:

The leading contenders offered tough if slightly measured responses when asked if they would take military action without consulting Congress to stop Iran from acquiring nuclear weapons. But Mr. Romney, the first to answer, seemed caught off guard.

“We’re going to let the lawyers sort out what he needed to do and what he didn’t need to do, but certainly what you want to do is to have the agreement of all the people in leadership of our government, as well as our friends around the world where those circumstances are available,” Mr. Romney said.

…

Representative Ron Paul of Texas said he would absolutely consult Congress and belittled Mr. Romney’s answer. “This idea of going and talking to attorneys totally baffles me,” Mr. Paul said. “Why don’t we just open up the Constitution and read it? You’re not allowed to go to war without a declaration of war.”

Romney and Giuliani Spar as New Guy Looks On – New York Times

Seems that Mr. Romney has little use for the Constitution:

Mr. Romney was sharpest in attacking Mr. Giuliani for efforts against
the line-item veto. “Mayor Giuliani took the line-item that the
president had all the way to the Supreme Court and took it away from
the president of the United States,” he said. “I think that was a
mistake.”

“You have to be honest with people, and you can’t fool all of the
people all of the time: the line-item veto is unconstitutional,” Mr.
Giuliani said, his comments directed at Mr. Romney.

He added: “The Supreme Court has ruled on it. So you can bang your head up against a stone wall all you want.”

For his part, Rudy G. kept up his tradition of unconditional support for losing causes and unpopular goats:

Debate co-host Chris Matthews asked Giuliani if Torre will keep his job. Giuliani answered “God willing.” He said Torre is the best manager in Yankees history.
Giuliani says Yankees manager should keep job – NewsFlash – mlive.com