I think this is a race that we simply can't count on any of the old models to understand. Even with almost all the polls looking bad for Trump, this race may come down to new voting blocks, the American Idol/Honey Boo Boo type voters who aren't voting based on positions but based on who they saw on TV, to be part of a pop culture event (like they voted for historic(sic) Obama). We may see groups of voters who never were active getting out.
This may go both ways though, it seems that DT is doing everything he can to turn off and frighten voters except for his most loyal demographics-- like he doesn't want to expand what he has.
Right now, both major party candidates have the worst trustworthy and likability numbers we've seen in candidates and both major parties have the highest percentage of #never members ever, so almost all bets are off.
I think things will become clearer once the debates start happening and the candidates are face to face, not on twitter or in more controlled environments.