By Christopher Ingraham

State legislators who support voter ID laws are motivated in no small part by racial bias, according to a new study from the University of Southern California. The study finds strong evidence that “discriminatory intent underlies legislative support for voter identification laws.”

The findings raise questions about the constitutionality of voter ID laws, which the Supreme Court affirmed in 2007 on the basis that Indiana’s strict law represented a “generally applicable, nondiscriminatory voting regulation.” For quick background, these laws require registered voters to show some sort of government-issued ID before they vote — supporters say they’re necessary to prevent voter fraud, while opponents counter that they disproportionately affect elderly, minority and low-income groups. For more, see ProPublica’s excellent backgrounder on the topic.