Not only did Trump pardon a criminal of a sheriff, Joe Arpaio, whose inhumane treatment of prisoners in Arizona did nothing to deter crime and everything to enforce racism. Now Trump has announced that he is lifting the ban on militarization of police weaponry that former President Barack Obama wisely imposed after the clashes in Ferguson, Missouri in 2014. This move on Trump's part means that police could once more transition away from viewing themselves as part of communities whose citizens they help by fostering conflict resolution and by taking criminals off the streets.
When militarization enters in, the situation is cast too sharply as a war, with an "us" (the police) and a "them" (anyone who might be perceived as resisting the police). Tanks and military-grade weaponry cause a community to feel intimidated. The warlike atmosphere generated by the military-style policing will set up warlike fear in the civilians instead of helping them trust that the police will protect them. Crime will be shielded and hidden from the Police Enemy instead of revealed and worked through, the way it can be by citizens whose police are a part of the community fabric.
Where will Trump's dreadful leadership take us? It isn't so much that we might go back to a bad time in the past. No return to the past is ever possible. The dread is for the bleak future toward which Trump is leading us.