My dream scenario would be for McMullin to win Utah, force an EC deadlock, and get the House to elect him president. Maybe only a 0.1% chance, but I can dream, right?
If the election goes to the House, Trump wins. Republicans have more state delegations.
Depending on the makeup of the Senate, you could theoretically get VP Kaine.
If the election goes to the House, then the Senate is almost certainly a Republican hold, and elects VP Pence. There are too many #NeverTrump House Republicans for Trump to possibly carry it, but there are also too many Trump loyalists for anyone to. There would be no winner and Pence would win the election. (I can provide a long version of this with likely House election results and names of #NeverTrump Republicans, but a quick look at Wikipedia would provide the same thing).
Any Republican could win in the House. But Trump cannot. And McMullin isn't running as a Republican, so that option is right out.
The Constitution gives one vote to each state, not proportional based on number of Reps in the delegation. In that scenario, Trump will take the majority of state delegations and win the Presidency, either by states voting as to whom the people voted for or voting as partisans.
The smaller rural states trend Republican.
The Constitution limits the choices to the top three contenders. So likely, it will be Trump, Hillary or Johnson in that scenario. McMuffin is poling nowhere near Johnson (or even Stein) right now. (unless they are talking "top 3 contenders by EV," the language from house.gov is unclear.)
Source:
http://history.house.gov/Institution/Electoral-College/Electoral-College/
