Louisiana voters are heading to the polls Saturday for a significantly revamped state primary, with a key focus on the political future of Republican U.S. Senator Bill Cassidy , who faces a challenge orchestrated by Donald Trump . Senator Cassidy is seeking a third term but must first navigate a Republican primary field that includes state Treasurer John Fleming and U.S. Representative Julia Letlow, the latter having received Trump’s endorsement in January. This election marks the latest instance of Trump seeking to exact retribution from perceived political adversaries, particularly fellow Republicans he deems disloyal. Cassidy has been a prominent figure on this list since his vote more than five years ago to convict Trump during his second impeachment trial, which followed the January 6, 2021, insurrection at the U.S. Capitol. Trump was ultimately acquitted. While Louisiana is not a state Democrats are targeting in their efforts to regain control of the U.S.…