If Trump drops out... then what?

[Acer]

I don't see this ending up in the House barring a tie [EDIT: if Trump drops before the election.] If the RNC fails to put a viable candidate on the ballot, it's their loss. There's no law that says the Republicans (or the Democrats) must have a viable candidate on the ballot for the election to be valid, so outside of a tie there would be nothing for the House to vote on. The legal wrangling in the states would be about changing who's name is on the ballot, but the election day is set. You don't make it in time, tough--still no requirement that you field a candidate just because you are the GOP. The courts have routinely relaxed ballot-qualification deadlines, but I can't imagine (hah!) they would or could relax Election Day.

The best case scenario for Republicans is that Trump wins the race, THEN drops before the swearing in, in which case the RNC can replace him with whoever they want. Chew on that for a moment... EDIT,not so sure about this part. Per Amendment 20, further reading suggests Congress would indeed be charged with solving the problem if the president-elect can't/won't serve. But again, they have to beat Hillary first.