I think the biggest drag on the Democrats right now is Manchin and Senema. Mitch has already said he's going to oppose everything. If he succeeds, then the Biden administration won't have much to brag about and will probably lose at least the Senate if not both houses in 2022 because of all the states' voter suppression laws. If he can get the new voting rights bill passed, he can keep control.
"Defund the police" was all about the 2020 election. "Modify the filibuster" is the most important factor now.