Trump didn't significantly grow his coalition and he didn't have to since Harris lost a good chunk of Obama and Biden voters.
Democrats are going to blame non-voters for Trump winning. Fine.
But it's pretty clear Harris and Democrats in general bled support from Black voters, Latinos, Arabs, Muslims, and others because of their pursuit of white conservatives and an economy most people think sucks.
The "radicals" of the party like Ilhan Omar and Rashida Tlaib did just fine in comparison.