Reminder—under the Debt Clause of the Fourteenth Amendment to the Constitution, the United States cannot default on the debt. Any law purporting to allow a debt default, such as the debt ceiling, is explicitly unconstitutional. For the US to default, the Constitution must be amended. The debt ceiling crisis is theater. Always has been.
Section 4 of the Fourteenth Amendment:
The validity of the public debt of the United States, authorized by law, including debts incurred for payment of pensions and bounties for services in suppressing insurrection or rebellion, shall not be questioned. But neither the United States nor any State shall assume or pay any debt or obligation incurred in aid of insurrection or rebellion against the United States, or any claim for the loss or emancipation of any slave; but all such debts, obligations and claims shall be held illegal and void.
If Congress will not act to pay the public debt, the Executive must act to pay the bills. If Congress and the President will not act, the Court must compel payment of the debt.
Threatening a default is an empty threat.