Democrats will rightfully spend considerable effort trying to re-capture Michigan, Pennsylvania and Wisconsin. Of the three, Wisconsin is likely to be the toughest. That's why Democrats should also concentrate on taking Arizona in 2020--a near perfect substitute for losing Wisconsin. Below is data from the Biden-Trump trial heat from the just-released Arizona State University/Latino Decisions poll. Biden leads Trump by 8, which is very promising. Note the white and Latino margins; Latinos are +37 for Biden, matching Clinton's +36 margin from 2016, according to States of Change data.
But among whites Trump is a mere +5, compared to his +16 over Clinton in 2016. That is a number that has to absolutely terrify the Trump campaign. They cannot win with such weak support among white voters.