Linda Greenhouse of The New York Times has the money graf:
As in many constitutional disputes, the choice of standard will drive the case. If strict scrutiny applies, the state will have to show not just that voter fraud is a valid reason for requiring identification, but that impersonating a registered voter is such a serious problem in Indiana that it justifies a remedy that will predictably deter members of identifiable groups from voting at all.
Supporters of Voter ID laws say we live in a society that requires identification; the "you have to show ID to write a check" argument is shopworn (and fast becoming outdated as people use debit cards to swipe away their money without every flashing a license). Writing a check isn't a right. Neither is driving. Both privileges require showing identification when asked. Voting is a right. Should government force you to show ID to exercise a right?