2018 elections if GOP wins White House

[Skill and Chance]

The dems will definitely gain quite a few governor's seats in this scenario but I think the GOP would gain senate seats since I believe a Republican president wouldn't do anything politically suicidal unless they're a true believer like Cruz or Huckabee.

Define politically suicidal for a Republican. As we saw in 2010, political suicide for Barack Obama was becoming President. I honestly think that what we've seen in North Carolina the past four years is a good example of what a Republican trifecta would look like at the federal level. A rabid, wild-eyed, right-wing Congress with Jeb Bush vetoing his own party's bills to try and save face.

Passing a national RFRA, invading Iran, blanket repeal of ACA, privatizing social security, banning Common Core, passing SOPA etc. Really I think it would be hard for Democrats to gain senate seats even if the pubs did 1 or 2 things like that since their defending so many more seats than the GOP is.

#1 and #3 together might be enough to drive a Dem wave, and would almost certainly fix the Dem midterm turnout problem.  #2 would if anything help the incumbent party due to the rally around the flag, as we saw in 2002.  Now if it turned ugly (and what intervention in the Middle East in US history hasn't?), it could result in a Dem wave in 2020 or 2022.  However, if they actually followed through on #3, that would flip the House and wipe out the Obama state R governors on its own IMO.  If they turn off white seniors, Dem turnout doesn't even matter.

I don't see Common Core or SOPA (outside of already very Dem tech areas) having legs with the electorate either way.  If they actually abolished the Department of Education, that would turn a lot of voters off, though.  Same with abolishing EPA or HUD.

[Skill and Chance]

Donnelly is a good campaigner. He represented one of the most conservative districts where the incumbent voted for Obamacare after 2010. I agree he will most likely lose than win if this is a neutral year/republican year. But he has political skills.

Travis Childers, Alison Grimes, Joe Dorman, Kay Hagan, Scott Brown, etc. Running a strong campaign often isn't enough these days.

Of course,
But this is annoying to read comments implying that Donnelly is doomed even with a republican president.

Sure, no one is saying that he is TOTALLY doomed. Anything can happen. Ron Johnson could win reelection next year, who knows.

No one is calling the WI Senate race anything more than Lean D, and some people still consider it a toss-up. Johnson already has a clear opponent (one who isn't a joke), and he's made no effort to moderate. Donnelly has no clear opponent, this race is more than three years out, and he has been much more moderate than the average Democratic senator, though he's no Manchin. By the same token, I don't think it makes sense to call this race anything other than Lean R, and I'd call it a Toss-up if Republicans win the WH in 2016.

Wulfric made some decent points, but Indiana is not as Republican-leaning as Tennessee (where I don't think any Democrat could win), and who's to say that Donnelly can't build a coalition in the same way that Bayh did? Berg wasn't as much of a joke as Mourdock, but if Heitkamp's win was a miracle, why would it happen again in 2018? There are some strongly Democratic leaning areas of Indiana, where a GOTV effort can prove crucial. A path to victory for a Democrat in North Dakota is much more narrow, even if there are fewer voters that need to be swayed.

ND will really come down to whether oil is still down in 2018 and who they credit/blame for it under a fully R-controlled government.