A lot of people also don't understand how the debt works. Banks bid on interest amounts to loan the federal government money every 2 weeks so that the govt can pay its bills. The oldest or the most costly debts are being paid back, while new ones are being borrowed. The US govt doesn't have a credit limit other than the "debt ceiling" which doesn't mean a whole lot since it keeps being raised.
The govt doesn't just go to Bank of America and say "hey bro can I have some more money on top of that 14T I owe ya? I promise I'll pay it back."
The consequence of such borrowing is just wasting money on interest rates, which is eating a huge amount of the budget. Defaulting on that debt however (declaring that it is impossible to pay back) would crash the value of the dollar and the world economy.