Selective enforcement is how you get a society that throws the book at black dudes smoking weed and looks the other way on white college kids doing the same. As a general rule I think it's a terrible way to structure a legal system, and I find it hard to blame a DA for doing DA shit.
DAs are always in an awkward compromise where they are reliant on police but also in the position to oversee and discipline them. If you go too far one way, you'll be unable to hire cops and do your job. Is there any evidence Harris looked the other way on some big scandal?
And anyway, this is all a distraction from the choice between Harris and Trump being plainly fucking obvious. Did you make the right choice or fail to be an adult?