Tump can only manage to get 38-42% of the vote in most polling. He's headed for double digit loses in all these states. Clinton probably gets 56-58% in Ohio if these trends keep up.
This was literally the same argument used against him in the GOP primaries.
38-42% is enough to win in a crowded field. In a two-way race, it's losing.
This. Plus, he was able to increase his polling as the race went on, candidates dropped out, and he won more states, but undecided voters rarely broke in his favor in an individual state. Winning 20 states on election day isn't going to give him a polling boost that he can take with him and win somewhere else.