“What’s wrong with some reasonable — non-discriminatory, may it please the court — measures meant to encourage turnout chiefly by those who exert themselves when turning out? What is the matter with some minimal formality, such as producing on demand a photo that verifies identity? The Texas photo ID law rebuked by an Obama-appointed federal judge as “an unconstitutional poll tax” permits the tendering of ID in various forms, including a citizenship certificate, a military ID card, and a concealed handgun license. That hardly strikes me (though I am not a federal judge) as troublesome or vexatious.”