Can someone explain why 538's fundamentals are 'faux fundamentals' rather than just stating it as fact? Something conflicting with your preconceived notions is not fact, and they clearly show where they're coming from with these numbers so it's not some magic number someone pulled out of their ass(unlike so many numbers on Atlas).
There is a breakdown of what goes into their "fundamentals"
https://projects.fivethirtyeight.com/2018-midterm-election-forecast/senate/north-dakota/
Heitkamp gets +13.6 for incumbency.
In particular, this advantage that the model is giving Heitkamp is so large because North Dakota is a small state.
He had to do that after Montana and North Dakota were the only two states he called wrong in 2012, and called badly wrong.
I believe that's what we call "overcorrection." Who says he was wrong because they were small states and not just due to random chance and sparse/bad polling?