sanders has drawn attention to an apparent truth: when turnout is high, democrats win. this is because the democrats have long been the quasi-populist party, whereas the republicans have been seen as fronts for deep money. i mean, the smart kids know better, but that's the popular perception, anyways.
that is about to flip over entirely this election, and it's also just another example of how clinton and sanders are really moving in drastically opposite directions. sanders knows he needs big turnout to have any chance and has been basing his entire campaign around it. but, if the election is trump v clinton and there's high turnout? clinton is going to lose. she actually wants to take more of a traditionally republican tactic, and try and suppress turnout - as she has been doing in the primary.
so, presuming that sanders does fall in line like he's expected to, you're going to end up in the situation where the republicans are trying to run as the populist party and get turnout up and the democrats are pushing the cynical vote suppression tactics designed to make people think it's not worth their time to bother voting.
the democrats have never been particularly inspiring, sure. but i don't think it's ever been this bad.