Unless the Democrats broke through in a true surprise state like Iowa (6 electors), Missouri (10), a Congressional District in Nebraska (1 of 5) or like President Obama Indiana (4), Trump would start with 21 states and 132 Electoral votes - so that is his floor. On the flip side unless Trump has a big upset in a state like Colorado (9), Maine (4 or a Congressional seat for 1), Minnesota (10) or New Mexico (5) then he will lose 17 states and DC which makes his ceiling 328.
This leaves 12 states in the middle that should determine the race. As of March 12, I ranked these states by the average of Trump vs. Biden state polls in March, or if there were no March polls then it is based on the most recent poll. Here are the results.
|Assume 21 Trump States||132||132|
|Assume 17 States & DC||210||538|
If Trump wins only the states in which he leads in the latest poll(s) then he takes Georgia, Texas, New Hampshire and Florida to get to 219 electors - 51 short of the 270 he needs to be re-elected. The one pickup from 2016 would be New Hampshire, where Trump led Biden in all three state polls in February.
If he also pulls off Arizona and Wisconsin, where he trails by 1 in the latest poll(s), he is at 240.
That means the Presidency would come down to a best two out of three of three states with between 15 and 18 electoral votes and where the latest poll(s) has Biden leading Trump by 2 to 3 points. Winning two of those three leaves Trump somewhere between 271 and 274 votes - a win though if he were to lose a couple of "faithless electors" like in 2016 close enough to be nervous.
Even though North Carolina was a 3-point lead for Biden among these three, it appears there is a more likely chance that Trump wins Ohio and North Carolina and loses Michigan and Nevada of the four states where Biden has between a 2 and 3 point lead.
Pennsylvania is one state that facing Biden rather than Bernie appears to hurt Trump, potentially because of progressive attempts to end fracking, which has led to an economic boom.