Just guessing of course... it would most likely fall to the Supreme Court and The Joint Military Chiefs to decide. I suspect there is at least a 20% chance for a military coup d'état which would most likely see the country divided into control sectors. There is one more probability that Speaker of the House Nancy Pelosi could become president but that scenario would need help from all of congress and that is doubtful. Should be a November to remember, glad I'm old.