It took about an hour for the lights to go out across Texas signalling the sudden end of the four-decade political career of ‘Big Bad’ John Cornyn, the long serving senator and one of the last holdouts of Bush-era Republicanism. As president Donald Trump had decreed with an 11th-hour endorsement of Cornyn’s party opponent, former state attorney general and Maga loyalist Ken Paxton, Texan Republicans moved in droves in the primary election run-off on Tuesday night. What had been an impossibly close race turned into a rout.Privately, Cornyn may have guessed at this outcome since Trump eventually gave his blessing to Paxton, predicting that he would win the primary “very substantially” before going on to defeat James Talarico, the charismatic gospel-quoting Democrat who the president described as “a very defective candidate”.“I think of what a wonderful experience I have had,” Cornyn had said early on Tuesday.“I can’t in good conscience turn this Red Senate seat over to someone who could likely to let it slip through their fingers to the detriment of Republicans in Texas, the Republican Party nationally and to the detriment of president Trump’s agenda. I feel a responsibility as a result of my long service.”None of that mattered once the poll booths closed after seven o’clock. Within an hour, it was obvious the wind was blowing in one direction. Cornyn just about kept his nose in front in the urban counties which house Dallas and Fort Worth while previously loyal counties across the state, most conspicuously in the Texas Panhandle, all voted according to president Trump’s endorsement. Former Texas attorney general Ken Paxton at a Grapevine Republican Club meeting, in Grapevine, Texas. Photograph: Desiree Rios/The New York Times