Debt ceiling law unconstitutional?

Another fight over the debt ceiling is looming, with Republicans threatening to force a shutdown of government and default on the country's financial obligations. These are fights that neither party ever made before 2010 because there was enough bipartisan sense of responsibility to recognize that the country must pay its bills and keep functioning to serve public needs.

There have been theories circulating of ways around the law to avoid such catastrophes, including a provision of the 14th Amendment that appears to obligate the country to pay its debts -- and the Constitution trumps Congressional legislation -- and a provision in law that might allow Treasury to mint a Trillion Dollar Platinum coin and deposit it with the Fed to cover the country's bills without further borrowing for some period of time. The defenders of the coin idea make the point that it's no more ridiculous than the Republicans holding the country's economy hostage. 

I have had a different thought on Constitutionality. Here is a comment on the subject I haven't seen anyone else make that I put on a another site:  

To avoid the apparent gimmickry of the coin, consider a broader Constitutional argument, broader even than the 14th Amendment provision: Congress ordered the President to spend the money with full knowledge that tax revenues would be insufficient to cover all appropriated expenditures. Authorizing expenditure assumes exercise of the Executive power to pay for it, and here, accordingly, Congress has already authorized the borrowing necessary to pay for it. For Congress to then say that the President may not exercise the Executive power to pay the bills for spending Congress ordered is to interfere unconstitutionally with the executive power to enforce the laws. 

Other than simply treating the statute as flat-out unconstitutional, perhaps there is a way for it to be treated as a soft cap in order to meet the conflicting requirements of all legislation and maintenance of a functioning government. It does seem the President should have the authority of a national emergency nature not to treat the law as a suicide pact requiring the United States of America to break other laws, including basic laws of contract with an international component that would involve treaties as well, and to stop its government from functioning at great danger to the public.

I don't know. Seems like a good argument to me. It's not as if there is a whole lot of precedent to deal with, and I don't know what recourse there would be other than impeachment -- impeachment attacking the President for saving the country from disaster, and with a Democratic Senate! (Remember, in impeachment, the House indicts and the Senate tries the case with final decision responsibility. There is no Supreme Court role at all other than the Chief Justice presiding.) I cannot see who would have standing to bring a suit in the courts other than Congress as a whole -- again, a Congress with a Democratic Senate. The Bush administration didn't hesitate much to assert Executive Branch power where it was less than clear. Why should Democrats always be the cross-every-t hand-wringers, especially when their assertions were to fight a war based on lies and defy the Bill of Rights and international law, while ours would be to save the country from real danger?