If we had a poll showing SC at Trump +3, I wouldn’t call that a tossup.
Trump won South Carolina by 14 points. Clinton won Minnesota won by 1.5 points.
The U.S. is swinging 5-8 points to the left from 2016 to 2020, making Minnesota and South Carolina equally distant from the 50-50 mark.
Any other argument that MN is special and is a toss-up based on a D+3 in an R internal would rely on a magical concept of "momentum" where Trump rising (possibly) to Biden +3 means that he can keep coasting up and over Biden's numbers, which is not how elections work.
In reality, both Minnesota and South Carolina have shown themselves to have low ceilings for one of the parties.
Ah yes if you think it's going to be a mini landslide for Biden and the race is locked in with a big Biden lead similar to Obama '08, then I guess maybe South Carolina could be as competitive as Minnesota.
I think a big Biden win is possible, but nothing is locked and I think looking at the 2016 map for the incumbent is at least as reasonable as looking at a myriad of polls. And I don't think the 1.5 2016 margin in Minnesota can be set aside because of polls, especially in light of 2016 polls.
