The theory, from the Republican perspective, used to be that the people who really care about it, are the ones who learn a lot on the subject and put up with hardship to vote.
Thus a rainy November, especially on election day, is Republican weather.
The Democrats seem to understand this the same way, thus everything that makes voting easy to accomplish they favor.
Does Donald Trump disrupt this whole concept?
I note that numbers are up for Republican voters so far in the primaries.
Perhaps Trump is exciting some people who would usually be apathetic?