It is getting harder to tell the right-wing nut jobs who shoot law enforcement officers from the right-wing politicians running for president. America has always had its share of John Birchers hoarding guns for a coming revolution. What’s new is that the GOP has mainstreamed radicalism and turned violently anti-government rhetoric into Republican Party doctrine.This kind of thing has been bubbling in the Republican Party stew since Barack Obama won in 2008, and it used to be a bigger deal.