Yesterday, a Pennsylvania judge rejected a challenge to a state law that requires photo identification to vote in Pennsylvania. Far from a radical finding, the Washington Post reminds us that photo ID requirements are legal under the U.S. Constitution according to the U.S. Supreme Court, and, in the Court's view, are a reasonable step toward addressing a serious public concern.

While the [Pennsylvania] challenge was brought under the state constitution, Simpson's opinion was heavily influenced by the U.S. Supreme Court's 2008 decision that seemed to give states the green light to require voters to present photo IDs. In the court's lead opinion, Justice John Paul Stevens, now retired, said that such a law in Indiana was a reasonable reaction to the threat of voter fraud, "amply justified by the valid interest in protecting the integrity and reliability of the electoral process."

The Supreme Court's ruling in that case had a very clear majority, 6-3, and received the support of one of the most liberal justices on the Court at that time, John Paul Stevens. Photo voter ID is not some radical proposal. It is a rational reaction to the concerns attendant to a system where we want every legal voter's voice to be heard. As I have argued, if even 1 percent of the vote is fraudulent in an election, how many important races could that swing? If there are ways to prevent that sort of fraud and reaffirm our commitment to ensuring voters' votes are protected, why wouldn't we pursue them? Missouri elections would benefit from similar photo ID rules.