ITHACA, NY—Everyone has the right to change their mind. When you’re a federal Court of Appeals judge who wrote a decision later upheld by the U.S. Supreme Court, though, your reversal is bound to cause commotion.

In 2007, Richard Posner, who sits on the U.S. Court of Appeals for the Seventh Circuit, issued a ruling upholding a controversial Indiana state law that requires voters display photo identification to cast their ballot. A year later the Supreme Court upheld Posner’s ruling. But earlier this month, the judge admitted he got the decision wrong during an interview on the HuffPost Live web program “Legalese It!”

“It doesn't happen very often where you see someone who's given down a ruling that something is perfectly legal and constitutional, to years later come back and say 'You know, I was wrong, and here's why,’” said Donathan Brown, assistant professor of communication studies at Ithaca College.

“It's a really rare turn-around, and that is what's catching most pundits and opinion-makers by surprise,” Brown added.

Brown, whose research on race and public policy includes voter ID laws, cites Posner’s decision in Crawford v. Marion County as paving the way for recent successful challenges to the Voting Rights Act of 1965. Earlier this summer, the Supreme Court found Section 4 of that landmark piece of legislation unconstitutional, rendering other parts impotent.

“And that's what Posner was kind of kicking himself in the behind about, because obviously he was fundamental in developing the legal precedence," Brown said.

Brown says the U.S. Department of Justice, which is attempting to challenge voter identification laws in states including North Carolina, now has its hands tied because the mechanism it used to block these laws – the Voting Rights Act – is now unconstitutional.

“They have the incredibly difficult task of proving that discriminatory intent was the purpose for which this new law was introduced [in North Carolina]. Good luck to them, but that's going to be a very challenging argument to make,” Brown said.