NYTimes.com: Laurence H. Tribe: We Cannot Pretend the Debt Ceiling Is Unconstitutional:
The White House and Congressional Republicans agree in principle that the debt ceiling needs to be raised, but they are at an impasse on how to constrain the deficit’s rapid growth. Meanwhile, some people have theorized that there’s a way to get around the debt limit.Several law professors and senators, and even Treasury Secretary Timothy F. Geithner, have suggested that section 4 of the 14th Amendment, known as the public debt clause, might provide a silver bullet. This provision states that “the validity of the public debt of the United States, authorized by law ... shall not be questioned.” They argue that the public debt clause is sufficient to nullify the ceiling — or can be used to permit the president to borrow money without regard to the ceiling.
Tribe later concludes:
The Constitution grants only Congress — not the president — the power “to borrow money on the credit of the United States.” Nothing in the 14th Amendment or in any other constitutional provision suggests that the president may usurp legislative power to prevent a violation of the Constitution.
Read the whole thing and remember that Tribe was once considered a potential Clinton Supreme Court nominee.