A national group led by former Attorney General Eric Holder filed a lawsuit on Monday against Wisconsin Gov. Scott Walker for refusing to hold elections to fill two vacant seats in the state legislature.

Why it matters: The seats have been vacant since last December when Walker, a Republican, tapped representatives from both to join his administration. Walker rejected calls to hold special elections before November's midterms, saying they'd be a waste of money given the legislature will adjourn in May. But Democrats and Holders' group argue that residents would be denied representation for more than a year since the Republican-controlled General Assembly won't convene until Jan. 2019

The backdrop: The suit was filed in a Wisconsin court on behalf of voters in the two vacant districts. This comes after Democrats flipped a Wisconsin district in a special election last month.