I think he is explicitly and for no other purpose pardoning and showing favor to overtly corrupt people (like his DOJ withdrawing charges against NYC mayor Adams), because those are the people he wants in positions of control regardless of party. It may seem like, "what is he even doing paying attention to this Democrat from years ago," but it's a signal to everyone that as long as they swear fealty, they will be allowed to exercise unchecked power and self-interest.
It fits into the J6 pardons as well. It also is (surprise, surprise) exactly how Russia operates.