Yes, we all know Hillary had a late stretch crash. No need to rehash all the explanations for that. But, a few things are different this time:Hillary had a 10% lead in MN the week before the 2016 election. She won by 1.5%.
1) Trump is an incumbent with a record that speaks for itself. Except for a few weeks at the beginning of his presidency, he has been underwater in approval ratings for his entire tenure. In 2016, it wasn't unreasonable to give him the benefit of the doubt about his professed intentions but he's told so many lies over the last 4 years that his credibility is shot with all but the true believers.
2) We have a different candidate. He may not be as sharp as Hillary but he's not nearly as unpopular either.
3) Hillary lost in 2016 because of the Democratic undervote that was particularly strong in the midwest. The primary reasons for that were 1) anger and resentment among the Bernie supporters and 2) a lot of voters just didn't believe that Trump would win. #1 isn't much of a problem this time and no Democratic voter is going to assume #2 anymore.