“With just days until Texas’ primary, Republicans in Washington are growing more alarmed that their increasingly vicious intraparty contest could cost them a must-win Senate seat,” Politico reports.“Sen. John Cornyn appears to be headed to an expensive and nasty 10-week runoff against Texas Attorney General Ken Paxton, with a strong chance that Paxton wins the nomination even after national Republicans spent months airing his dirty laundry all over the Texas airwaves in an effort to boost Cornyn.”