The votes are the middle.
Candidates who veer too far to the left or the right don’t win elections. (Disclaimer: I’m talking mostly about Presidential and Senatorial races here; if you come from a small district that is very conservative or very liberal, then your “middle” is in a different place.)
The GOP has been nominating people far to the right lately in many races, and looks to be headed that way in the 2016 Presidential race unless they come to their senses. Some clueless Republicans think that if they had nominated someone more conservative than Romney, they would have done better. Their lack of success with very right wing Senatorial candidates even in Republican states shows that this is not true.
The Democrats have won 5 of the last 6 Presidential races with moderate candidates. (Aside #1: I am counting Gore as a “win” for the purposes of this because he did win the popular vote and would have been President save one Supreme Court justice. Aside #2: Don’t go telling me Clinton and Obama are “liberals.” They only seem that way compared to Republicans.)
So the question now is: Could the Democrats go farther left, since the Republicans will most likely nominate someone so far to the right that they will alienate most moderate voters?
No matter how people identify themselves, the fact remains that the majority of Americans support many liberal ideas. They want abortion to be legal; they favor gay marriage; they like medicare, medicaid, and even Obamacare; they want marijuana legal; they support environmental laws; and when their government is taken away during a shutdown, they discover they actually like a lot of the things the government does. Could the Democrats nominate a real liberal — Elizabeth Warren or Bernie Sanders or Al Franken or someone?
Given the choice of the crazy person and the liberal, the Americans might make the right choice.