Default can only happen if the US fails to make a contractual payment on debt on NOTES, per schedule.
There is no question but that even as the DemoPublicans whine about restrictions on their credit cards they still have plenty of cash in the bank (taken from private citizens' bank accounts by force, let us never forget) to pay the interest on all bonds and other contractual debt obligations. They don't need to borrow one penny to pay all the interest. They could pay the interest many times over and still wouldn't need to borrow a penny more than they already have.
So those who talk of "default" are either too stupid to live or too corrupt and lying to be either in office, in bureaucracy, or in journalism. Take your pick: stupid or lying. Is Obama stupid or lying? How about "Turbo Timmy" Geitner?
The issue isn't whether failure to raise the debt ceiling could trigger a "default" it is only whether failure to raise the debt ceiling might get in the way of ordering more PORK for dinner at the White House or killing civilians in this and other countries. Obviously the politicos DESPERATELY want their PORK and killing to proceed and increase. And, apparently, a lot of corporate types who have Fascist inclinations feel similarly.
P.S. In addition, the Treasury has the authority to PRINT unbacked dollars, if necessary, to pay interest or just to buy pork and beings. So warnings of "default" are truly idiotic or just plain ugly and naked propaganda. Get a brain.
I have come to realize that men are not born to be free. Liberty is a need felt by a small class of people whom nature has endowed with nobler minds than the mass of men. -Napoleon