It's been decades of Whites dealing with harassment by the foreign enclaves that have set up in the Western world. They could just kill them. As long as law enforcement knows they're next if they stand in the way, they'll stand down or look the other way, if not join in the purge. It doesn't take too many instances of mobs burning down court houses and police stations before a government realizes they can't get away with something. And the projections that the US population can't take on the US military are wrong. They're totally predicated on people fighting with guns, but chemical or biological weapons that the US population are capable of producing could easily wipe out an entire military base from miles away. Then there are EMPs and jammers that could wipe out radio communication and smoke could be used to prevent laser communications, making it impossible for the military or law enforcement to coordinate. But this is all assuming the military wouldn't defect or undergo an internal coup.