WillK, I'm on such a contract as well.
But those contracts are paid out of discretionary spending, and as you know the total sum of discretionary spending is less than the difference between the size of the deficit and mandatory spending. In other words, there would be no way for the government to balance its budget tommorrow without violating those contracts. And between a constitutional amendment and a legal contract, the Courts would surely recognize the Constitution as the higher law of the land and strike down your contract as unConstitutional.
With regard to your point on cash flows, that is a short term problem that would be corrected within a year as the Treasury learns how to operate on a much smaller pile.
The bigger point here is that not raising the debt ceiling for the rest of the Obama Presidency affects on the present generation, while a constitutional amendment would bind all future generations. There is really no comparison.
Actually if the courts got involved, which I sincerely hope doesn't happen, they'd probably order a reduction in programs such as Social Security. Payment of Social Security is not a contractual obligation of the Federal government. While it would be politically impossible to do so, legally Social Security could be repealed tomorrow and all those expecting to get paid would have no legal recourse.