How large would the swings be if Rural Frost Belt Whites voted like they did in Missouri:
Darker red is a larger swing towards the Republican Party, increments of 5% (Margin)
Here's how those states would've voted in the 2020 US Presidential election assuming all else remained the same except with the above change in the rural White vote:
R+31.71 - MAINE
R+31.57 - NEW HAMPSHIRE
R+26.17 - VERMONT
R+24.10 - IOWA
R+22.20 - INDIANA
R+15.29 - WISCONSIN
R+11.80 - OHIO
R+7.00 - PENNSYLVANIA
R+6.77 - MICHIGAN
R+3.02 - MINNESOTA
D+12.15 - ILLINOIS
D+16.61 - NEW YORK
Mainly shows that there really isn't that much more room to fall for Dems in Ohio and Downstate Illinois, and any collapse in Rural Minnesota won't put the state out of reach, especially considering growth in MSP.
However, they should be worried certainly about Wisconsin and Upstate New England.
Here's how an election might look like in this scenario:
Thankfully 2022's results make this scenario seem less likely.