“This spring, President Trump easily dispensed with Republicans who had crossed him in a display of raw power that seemed to underscore his iron grip on the party’s base. One by one, Senator Bill Cassidy of Louisiana, Representative Thomas Massie of Kentucky and Senator John Cornyn of Texas all fell to challengers backed by Mr. Trump,” the New York Times reports.“The spring of retribution, however, has given way to a more complicated summer.”“A series of losses by Trump-endorsed candidates has eroded his winning record, raising fresh questions about whether a president approaching lame-duck status can still exert as much control as he wants over his party’s voters.”