HARRISBURG, Pa. (AP) — The U.S. Justice Department sued six more states on Thursday, saying the states are illegally blocking the agency’s wide-ranging effort to scrutinize detailed voter data in a brewing court fight over what states say is the private, protected information of residents.

The Justice Department also accused the states of failing to respond sufficiently to questions about the procedures they take to maintain voter rolls.

The department’s newest lawsuits targeted California, Michigan, Minnesota, New York, New Hampshire and Pennsylvania after it sued Oregon and Maine last week and has said it is mounting a nationwide effort to ensure that states are complying with federal requirements to maintain voter rolls.

“Clean voter rolls are the foundation of free and fair elections,” Attorney General Pamela Bondi said in a statement. “Every state has a responsibility to ensure that voter registration records are accurate, accessible, and secure — states that don’t fulfill that obligation will see this Department of Justice in court.”

All eight states being sued are led by Democratic governors, except for New Hampshire, which is led by a Republican.