Texas Attorney General Ken Paxton’s U.S. Senate campaign released its first political advertisement of the hotly contested Senate primary race targeting Sen. John Cornyn, marking an escalation in a race that’s been expected to have plenty of fireworks. The ad centers on past remarks by U.S. Rep. Jasmine Crockett praising Cornyn’s bipartisan cooperation, a theme Paxton’s campaign is using to frame the incumbent senator’s record as increasingly aligned with cross-party dealmaking. The release comes as Cornyn’s Republican challengers have publicly criticized him for declining to participate in debates. The advertisement strings together clips in which Crockett describes Cornyn as “helpful”...