DOJ's probe marks the first time it has publicly acknowledged a formal investigation of a voter ID law passed in a state which is not covered by Section 5 of the Voting Rights Act, which requires certain states with a history of racial discrimination to have changes to their voting laws precleared. The Pennsylvania investigation falls under Section 2 of the VRA, which prohibits any state from enacting a "voting standard, practice, or procedure that results in the denial or abridgement of the right of any citizen to vote on account of race, color, or membership in a language minority group."
As TPM explained last year, the Supreme Court would likely be skeptical of a Section 2 case given that it ruled to uphold Indiana's voter ID law in 2008. Samuel Bagenstos, who previously served as the number two official in the Civil Rights Division during the Obama administration, said DOJ would need to show that there was a significant racial disparity and that the burden of obtaining photo ID is significant. Many believe that Section 2 cases can only be brought after an election has taken place so that DOJ could present direct evidence that the law had a discriminatory effect, but civil rights groups have pushed DOJ to sue over voter ID laws in non-Section 5 states.
DOJ has already opposed voter ID laws in South Carolina and Texas, two states which are covered by Section 5 of the Voting Rights Act. A panel of federal judges heard the Texas case earlier this month, while judges will hear South Carolina's case later this summer.
Corbett's office did not immediately respond to TPM's request for comment. Perez's letter to Pennsylvania is embedded below.
(Ed. note: The story has been updated with additional information about the letter.)