As we saw in the Republican Party, two establishment v. base fights(McCain v. Huckabee, Paul; Romney v. Santorum, Gingrich, Paul) lead to the rise of someone despised by both the establishment and the base. I suspect the Democrats may have their own Trump arise. Maybe Roseanne Barr?
Alternatively, we'll end up with someone more like FDR, who is acceptable to both the establishment and the base, but leans anti-establishment.
For the record, I think the winner will be a sort of mild anti-establishment figure or platform. Trump is becoming the establishment, and I think he'll do a lot to discredit it. Running as anti-DC, anti-capitalism, and probably as anti-foreign intervention (I think Trump will get involved in at least one stupid and unpopular war) will be pretty popular after 4-8 years of President Pussygrabber in charge of the military, the government, and deregulation.