“Romney” is good speculation - that makes more sense than one currently in the GOP primary race jump to third party. The principle of “not in either party” worked for Murkowski, but it can’t work on a presidential election because that election is indirect. Voters vote for party electors, not for a candidate.
You make a good point.
That’s why Clinton won with 43% of the popular vote but more than DOUBLE the ev numbers of Bush.