Why is Tester doing so much better than Heitkamp?

[Florida Man for Crime]

Because believe it or not, North Dakota and Montana are different states.

This.

Like I said in another thread, Montana is not really a truly "rural" state in the same way or to nearly the same extent that North Dakota is. The land use patterns are very different, and this leads to very different politics. The part of Montana that is receptive to Democrats is primarily in the western Rockies. The part of North Dakota that is (somewhat) receptive to Democrats is primarily New-Collin-Peterson-esota.