Texas governor Greg Abbott will never be mistaken for Vladimir I. Lenin‚ but his role during the border crisis recalls the revolutionary’s famous line about “heightening the contradictions.” It is‚ of course‚ beyond Abbott’s power to secure the border in the teeth of a determined federal policy of nonenforcement. Still‚ he’s used the instruments available to him to force sanctuary-city mayors to confront the consequences of their own professed beliefs on immigration and to bait the Biden...