In 'normal' times the deployment of the National Guard would be much less controversial, as it has been when the NY ARNG deployed to help with security in NYC at times. But this seems to be deliberately confrontational and possibly prepping for something much bigger and far more intrusive, planting at flag so to speak before pushing for more, and more...and more.
The number of Guardsmen being deployed is not significant, 200 to start so you are talking about having ~50 on duty at one time, a small enough number that frankly probably could be done by other Federal law enforcement as it has been done in the past. A much larger role for the Guard and the military in domestic law enforcement has been and continues to be advocated by current government officials, so it really isn't a stretch to think this is only the beginning of a much larger push for a military role in domestic law enforcement.