Dane County Judge Maryann Sumi ruled Thursday to allow two more groups to join Attorney General J.B. Van Hollen's lawsuit over voter registration checks.
The Milwaukee National Association for the Advancement of Colored People and the Milwaukee Teachers' Education Association will join the case, bringing the total number of parties to nine.
The other parties involved are Van Hollen, the Government Accountability Board, the Democratic Party of Wisconsin, the Republican Party of Wisconsin, the American Federation of Teachers-Wisconsin, Madison Teachers Inc. and Madison Firefighters Local 311.
Van Hollen sued the GAB last month over its failure to comply with a federal law requiring state voting agencies to cross-check voter databases with driver's licenses or social security numbers.
Richard Saks, the attorney representing Milwaukee NAACP, said minority voters would be hurt if Van Hollen wins this case because many black citizens, especially in Milwaukee, lack valid driver's licenses.
Saks said they would have to rely on social security numbers, which have an almost 50 percent mismatch rate.
There would be large, large numbers of minority voters who would end up being found ineligible to vote in the upcoming election,"" Saks said.
UW-Madison professor of law Frank Tuerkheimer said all the parties added onto the lawsuit would probably not slow down the proceedings because they will have to accommodate the existing schedule.
