The fall of John Cornyn mirrors the fall of the Republican party | Sidney Blumenthal

The Texas senator was emblematic of the era between Reagan and Trump, as Republicans shifted from the party of business to a cult of personality

The defeat of John Cornyn is a milestone in the downfall of the Republican party. His virtue for decades as a steady conservative institutionalist", as the New York Times described him, became his terminal liability. His expenditure of $92m, the greatest amount ever dropped by a candidate in a Senate primary, could not forestall his humiliation at the hands of the scoundrel Ken Paxton, with his lengthy rap sheet of allegations of bribery, abuse of office, felony securities fraud and impeachment by the Republican-controlled Texas House, along with his hostile divorce by his wife on biblical grounds". Despite Cornyn's blast of TV ads against Crooked Ken", the Home Wrecker", Paxton, carrying the imprimatur of Donald Trump, trounced him by 28 points. Immediately after the primary, the National Republican Senatorial Committee, which Cornyn had once led, set about scrubbing the ads as if there had been no Cornyn campaign at all and the villainous Paxton was the rightful successor to hold the Senate seat Cornyn had occupied for 24 years. The Orwellian erasure was a further measure of the relentless Trump effort to stamp out of existence the remnants of the old party and to build on its ashes his golden idol.

Cornyn's ignominious rejection is not his alone. His loss represents the ongoing shattering of the Republican party whose foundations were laid by Ronald Reagan, laboriously built in Texas by the Bushes, both father and son, with their operative Karl Rove, and, within the Senate, where Cornyn arrived in 2002, the ruling Republican structure established by Mitch McConnell. Cornyn rode on the Reagan wave that swept aside Democrats in Texas, to be raised up as a factotum of the Bush operation, and serve as the indispensable conduit of funds from the oil and gas industry to fuel McConnell's dark money machine that financed Republican candidates, destroyed campaign finance reform, and secured the conservative majority on the supreme court.

Sidney Blumenthal, former senior adviser to President Bill Clinton and Hillary Clinton, has published three books of a projected five-volume political life of Abraham Lincoln: A Self-Made Man, Wrestling With His Angel and All the Powers of Earth. He is a Guardian US columnist