the independents, that's what to watch in this. If they swing Trump then HIllary's done
Most of the young voting block that I know have leaned way left. As the race has progressed, many--perhaps most--have either gone straight to Johnson, or went to Johnson through Bernie. Now, most of them that I talk to say that if Johnson doesn't look like a viable winner, they
will probably vote for Trump.
They just distrust Hillary that much. And that's from the block of people that I know who have leaned predominately left.
I'm predicting that Trump will pick up a lot of votes in the independent block, not because they like him so much, or because they trust him so much, but simply because he'll look like the only viable candidate besides Hillary.
If the Dems are smart, they will spend a lot of effort propping Johnson up as a viable-that-will-not-be viable candidate to split the independent vote against trump. They need to make Johnson look like he has a chance, because if true independents get the impression that Johnson is a sunk ship, they will jump on Trump as the dingy that he is.
Then again, tat too may backfire, because if many people start thinking that Johnson isn't a wasted vote, he very well could be the next President. (And the country would win.)