Dear Ben,
They should. Once a mayor commits to protecting the city, in the current climate it could rapidly become uncontrollable. Some cities think they cannot or will not deal correctly with possible escalations, so they sit tight. Some (Ahem!) mayors are control freaks, and the idea of having a to admit they are losing and then regaining control, terrifies them.
I was asking if you are advocating for Federal Agents, like Portland has. I have no idea how it is helping. And it seems to be at least borderline unconstitutional. Is it a dress rehearsal?