Did Trump set a new trend in the Rust Belt?

[Virginiá]

If anything, he accelerated an existing trend. If he started a new one, it would be pretty hard to tell by just one election. However, let's keep something in mind here - just a little over 8 years ago, Obama won some of the rustbelt/GL states (MN, WI, MI, PA) by pretty overwhelmingly margins. Almost 14 points in WI, a whopping 16+ points in Michigan and 10 points in PA/MN.

Guess what happened ~8 years later? The Republican just barely eeked out a win in all but 1 of those, and came close in Minnesota. His wins were so tiny that a whole smörgåsbord of different circumstances could have swung them the other way. Perhaps if Clinton had campaigned more in those states. Or even more, if African American turnout didn't implode in WI/MI.

The point is, Trump has a lot less room to fall than Obama did, so it's very possible that Trump's gains are as temporary as Obama's were. It's quite possible that while Trump has (or had?) a small chance to lock in those gains, his constant scandal and ineffectiveness as a president may again forfeit them to the other party. Obama helped save the auto industry in some of these places, pushed stimulus to help the recovery, pushed to expand Medicaid and expand insurance coverage, and he still lost them. Do you think Trump can match that? Instead, what may be more likely is that Trump, as is the case for all Republicans since the late 60s, gets unlucky and hit with an economic contraction some time during his 1st term, gets labeled as a bogeyman who tried to take away everyone's insurance (or succeeds?) and a guy whose incompetence and lack of ethics resulted in 4 years of nothing but scandal. That is hardly the kind of administration you want to run if you're looking to solidify your coalition.

[Virginiá]

The GOP has long been in control of the Midwestern region. I will remind you that Republican governors and legislatures have been in power in Michigan, Wisconsin, Pennsylvania, Ohio, and Minnesota in the recent past. I don't have the statistics offhand, but I'm fairly sure that most of these states have had GOP legislatures from 2000-2016 for either the same amount of time the Democrats held them or longer.

Out of the states you listed, Pennsylvania, Ohio and Michigan have seen the largest amounts of GOP influence at the state level. They rule the roost in the legislature in those states, and have since at least the 90s in most cases. Further back in the case of PA, and both had dominant GOP control over at least one chamber in the 80s.

Minnesota is different in Democrats, before Dayton, actually hadn't held the governors mansion since the early 90s. They have held the legislature most of the time since the 70s though. Republicans have been doing better in the state House though. I'm quite curious how MN elections will turn out in 2018. It's a good chance to see just how sticky the trends under Trump are. Ideally, if he stays just as unpopular, you would really expect to see Republicans lose ground in the legislature and for Democrats to hold their own in most other offices.