Just something to ponder about.
There are 33 Senate seats up for election in 2018. Right now.....two Democrats are absolutely running for re-election. One Republican has already said he won't run again and will retire. Seven Republicans and twenty-one Democrats are in the "thinking" stage of running again. And at the end of this entire group.....two independents.....with both likely to run.
Right now, the general belief by various news groups is that there might be a challenge thrown up against the Republicans in place.....in Nevada and Arizona. I don't see this being affected by a President Hillary or a President Trump. It might be suggested that the Supreme Court choices under a President Hillary would make some residents in these two states get hyper and negative against Democrats.
As for the remaining states, mostly under Democrats? West Virginia, North Dakota and New Jersey might be states where a real Republican contender could win and take three more seats. In this case, a President Trump....on the campaign trail in the three states might help that candidate.
But there is this odd feature of a President Trump.....a number of GOP players went negative on him during this election. My humble guess is that there would be some pay-back. In Arizona's case, Republican Senator Jeff Flake went negative on Trump. So, Trump might come to campaign in the Republican primary for someone to replace Flake.
Currently in Nevada's Senate election situation (2016), the Republican running has gone negative on Trump, and found that he's now lost votes. Enough to lose the election? Yeah.
I think what you will see is a crowd of new faces in 2018, with several Republicans sent home (Senator Bob Corker of Tenn might be one who is replaced as well).