Because ICE has federal authority, anything local authority does will create a conflict that ICE and Trump will use to justify martial law.
In other words, the states shouldn't exercise their own authority or else the feds will keep escalating the things they're already doing? At this point I don't see any reason to believe that Trump won't declare martial law regardless of what Minnesota does. The question isn't whether or not he will escalate, it's whether or not there will be resistance.
On the one hand, I really really want it to be a world-changing breakthrough for real this time. I've been losing my dad to Alzheimer's for several years now and even if it's too late for him I would just hope that nobody else has to go through that in the future. On the other hand, knowing that it's someone's business model to jerk at my hope and heart-strings for ad engagement has me more or less ready to fire futurism into the fucking sun