SAINT CLAIRSVILLE, Ohio — Sen. Bernie Sanders, I-Vt., who has retained counsel as the FBI investigates whether his wife, Jan, committed fraud to acquire a loan for a now-shuttered Vermont college, predicted Saturday night that the probe would be a political fizzle. “This was a story that just, amazingly enough, came out in the middle of my presidential campaign, initiated by Donald Trump’s campaign manager in Vermont,” Sanders said in an interview, between rallies in Pennsylvania and Ohio organized to defeat the Senate Republicans’ health-care bill.