Sen. Jay Rockefeller and West Virginia were an odd mix at first—a Harvard-educated native New Yorker from one of the nation’s richest families arriving in one of the poorest states. Through a half century of public service, he made it work. And as he heads into retirement as the last member of the Rockefeller family dynasty in political office—and the only Democrat—the five-term U.S. senator leaves a blueprint for fighting to fix real-life problems for burdened families and to protect the nation’s coal miners. […] Rockefeller was the state’s junior senator for 25 years, yet carved his own path of...