The Left wants the Right to commit suicide over matters that are trivial compared to the $4 trillion government coup d'tat of America. The Right seems willing to oblige. If the Right doesn't get its act together and unite against this one HUGE issue, we'll have to look somewhere other than elections to find deliverance from our would-be slave-masters.
Having said that, do you know of a valid argument that a federal requirement for a photo ID to vote would be unconstitutional?
No, of COURSE requiring a photo ID to vote would not be unconstitutional. But if it is, so also it is for buying or selling guns, including Class III items.