A new biography of William F. Buckley Jr. raises questions about his responsibility for Trumpism. William F. Buckley Jr. was a key figure in the ascent of conservatism from fringe movement to the highest reaches of power. | Evening Standard/Getty Images Jeff Greenfield is a five-time Emmy-winning network television analyst and author. I’ve often wondered what William F. Buckley Jr., the most influential conservative of the 20th century, would make of Donald Trump as president.