American Zeroes by John DiFelice

Alt-right ideologue Jeremiah Stumpf thinks his next door neighbors are terrorists.  Between counting and recounting his cache of gold and silver coins, cleaning his assault weapons, and emailing Paul Ronsen, his Libertarian superhero, Jeremiah devises a plan to deal with his neighbors in a way that is uniquely American. Unfortunately, his neighbors are not what he thinks they are. They are something much worse, something beyond his comprehension.