Apologies if I'm repeating a PD post.
Dems couldn't take the Michigan legislature because there were too many incumbents. Gerrymanders aside, there's usually a main party in each district and they typically only lose when it's an open seat. They reduced the majorities, but the R's had built them up too much.
D's also won all the state-level offices which is not unusual, the Governor winner usually takes the others, but the Secretary of State went D for the first time since the Jurassic Period.
Basically every kind of proposal won in Michigan. The state ones: Regulating and taxing pot, establishing a redistricting commission that's evenly balanced between the parties, and adding a bunch of stupid shit about voting to the Constitution that sounds good but should be laws especially since some of them are borderline inherently contradictory.