Washington — Louisianans are voting Saturday in the state's Senate primaries as Sen. Bill Cassidy fights to hold onto his seat.  A handful of Republicans are facing off Saturday in a competitive primary to win the GOP nomination as Cassidy — a Republican who has occasionally broken with his party — seeks a third term in the Senate.  Cassidy, 68, was one of seven Senate Republicans who voted to convict Mr. Trump in his impeachment trial after the Jan. 6 attack on the Capitol in 2021. And