The one thing most haven't mentioned if it looks like it will be a huge landslide in the Presidency do you start to see voters looking at electing a strong opposition. Remember Clinton despite being well ahead is still not particularly well liked or trusted by a majority of voters. I think you may see an effect where in Atlas blue states like Missouri, Indiana where voters become more interested in keeping Clinton accountable by supporting the Republican candidate. This probably will be less of a factor in Wisconsin, Illinois, NH, Nevada though and Democratic held Senate seats. Not suggesting it will play a huge roll but I think this could still be in play.
Almost all of the voters thinking this way will likely vote for Trump anyway.
The voters most likely to take that stance are independents, and right now I don't think Trump is winning them.
