Section 4
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.
While it is possible that the United States could default, a naked short to take that position would be like saying, "Hey, I bet you $100 that this steamroller will stop if I jump right in front of it."
If you think the US will default, it might be wiser to go long something that will grow in value in the chaos that would immediately follow.
None of the actors in Florida control the federal executive.