It was just 15 months ago that Bernie Sanders ended his campaign for the Democratic presidential nomination, but by his own telling, he’s already converted that political insurgency into a movement that’s changed what’s considered mainstream in America, from a $15 minimum wage to universal healthcare. In his new book, Bernie Sanders Guide to Political Revolution, he distills what he’s learned into a how-to for grassroots activists. But with Hillary Clinton still on a book-tour putting part of the blame for Trump’s victory on Sanders, the self-described socialist is clearly feeling contentious, and puts plenty of blame back on Clinton and an “upper-middle-class” Democratic party, which he joined in 2015 to run for president.