Maybe. Have the Rs maxed out? Is this it? One of the biggest, if not the biggest, factor will be Trump's performance, or at least the perception of his performance. I have drawn the Reagan analogy here since Day One. Back in the early 80s, the Dems and the media bashed Reagan every single day (sound familiar?). But it did not work because Reagan turned the US machine around (which was left in shambles by Carter (and Nixon even)). Twenty years later, they all offered nothing but praise for Reagan, as if they had all along. Will this repeat?
There are, of course, other factors. Let me give you one example. Polling of Dems say 57% want a candidate under 60, and 77% want one under 70. As of today, the Dems leaders are Joe Biden at 31%, Bernie at 24% and Liz Warren at 16%.
http://www.publicpolicypolling.com/...lings-on-2020-field.html?mod=djemBestOfTheWeb
On Election Day 2020, Biden will be 77, Bernie 79 and Warren will be a spring chicken at 71. So, it is not and will not be all about Trump. The Dems have to put something and someone forward as well. As I have argued here, I hope they just keep doing what they have been doing.