I don't think the electorate is moving much at all in either direction. I think most people are pretty unwavering in their beliefs once they get to a relatively mature age. The big changes occur in the relative importance of the issues. There are some issues I lean left/libertarian on (especially social issues), but they just aren't important enough to me to have any meaningful impact on my vote. I'm not going to vote for socialism because the capitalist in the race believes earth is 6,000 years old or marijuana dealers should go to jail or the Egyptian pyramids were built to store grain. While those positions are laughable, they are so inconsequential to my life that when the left kicks and screams over them, it actually insults my intelligence to the point that I get more motivated to vote.

That said, the relative importance of issues change. For instance, hypothecally speaking, if Trump were to actually start throwing gays in camps or reinstating Jim Crow laws, the relative importance of civil rights would go up and would motivate me to vote against those actions.