Montana

[Skill and Chance]

It's a similar dynamic to West Virginia, but the New Deal type Dem holdouts are even stronger in Montana because it doesn't have WV's social conservatism.  It used to be a Dem base state during 1896-1948.  The local economy hasn't changed nearly as much as the national economy since 1950, so statewide elections, which were still decided primarily on labor/class issues have diverged more and more from presidential elections.  If a Bernie type Dem gets the nomination in 2020, I think it would only be a 7%ish GOP win.

[Skill and Chance]

Unless an election is 2000-level close, it’s really not worth the time or resources to campaign in a 3-EV state. Thus these states tend to remain pretty solid for one party or another.

But they still have 2 Senate seats (which Democrats have somehow managed to do remarkably well in for decades even as their presidential candidates get blown out most of the time).

Democrats need to worry about the Senate going forward, particularly if they lose any more ground in New England.