Heather Mac Donald writes at The Wall Street Journal about how the Black Lives Matter movement and anti-police attitudes at the Obama DOJ have (1) given police realistic fear of random violence directed at them, (2) made police reluctant to enforce laws, and (2) consequently led to a sharp upturn in criminality. The police feel nobody in authority has their back, and that is uncomfortably close to the truth.
We know how this trend ends, with law-abiding Americans buying guns and defending themselves. That outcome isn't optimal. We need to move back to a "broken windows" policing model where the police believe, accurately, that they are the instrument of a society which has their back, which wants the laws enforced fully, carefully and without bias.