In a rational world, the debate over voter ID laws would be ended by the eloquent, incisive and angry opinion issued late last week by U.S. Circuit Judge Richard A. Posner of Chicago in a case concerning Wisconsin. But this isn’t a rational world. So not only will the debate continue, but Posner’s opinion failed even to sway his fellow judges on the 7th Circuit Court of Appeals. The court split 5-5 on Posner’s request for an en banc — that is, full court — rehearing of the Wisconsin case, in which a three-judge panel already had cleared the state’s ID law to go into effect for next month’s election. That meant Posner’s request was turned down and his opinion was in the nature of a dissent. As it happens, the Supreme Court has stepped in and suspended the Wisconsin law, probably invalidating it for the upcoming polls. But Posner’s 30-page dissent, laid out in his typical lucid and direct manner, is as exacting an examination as you’re likely to find of why voter ID laws are corrupt and iniquitous, and why their usual rationale — to combat voter fraud — is a lie.