I keep hearing that if we don't raise the Debt Ceiling by Aug. 2 or whatever the date will be, that we will default on payments on the country's National Debt.

Why will the National Debt be the one that is hit, instead of any of the other things the Fed govt pays money on? Like Social Security, or legislators' salaries, or any of the other usual expenses?

Is it because the National Debt is the only one that doesn't vote?

If we have to chop something, however temporarily, why not chop legislators' salaries, or funding for OSHA or ATF etc., instead of defaulting on the National Debt?