Donald Trump runs on fear. Once again, he\u2019s closing out an election season with a direct appeal to the darkest impulses of the American psyche. \u201cThe Democrats don\u2019t care what their extremist immigration agenda will do to your communities,\u201d he said at a rally in Arizona last week, packing xenophobia into the false assertion that \u201cDemocrats want to throw your borders wide open to deadly drugs and endless gangs.