The 14th Amendment to the Constitution of the United States says in part "the validity of the public debt of the United States...shall not be questioned."
The "debt ceiling" is an arbitrary number representing the amount of debt the Congress has decided the government will honor. The debt is incurred by the Congress. If the debt ceiling is not raised the Congress would refuse to pay its already incurred debts. This would be in direct conflict with the 14th Amendment.
The mere threat of non-payment in 2011 led to a reduction in our credit rating. The effect of the U.S. actually refusing to pay its debts could destroy our economy.
To threaten to hold our country hostage for non-payment of our debt is not politics, it is an act of terrorism and should be treated as such.