MILWAUKEE — Two days before Wisconsin's elections maps will be argued in what could be a landmark case before the U.S. Supreme Court, folks upset over what they say is a rigged system rallied in Milwaukee.

Holding signs "Democracy Demands Fair Maps" and "Fair Maps for Fair Elections," a crowd of around 150 people cheered and applauded speakers at the rally at Plymouth Church on Milwaukee's east side.

"I'm sort of insanely excited," Mary Lynne Donohue said shortly before the gathering.

Donohue, a resident of Wisconsin's 26th Assembly District in Sheboygan County, is a plaintiff in the suit and was flying to Washington, D.C., Monday morning.

"My role is to just sit and listen. It's such an important case, such a big issue. It's important for democracy," Donohue said.

A group of Wisconsin Democrats sued in 2015, arguing that the election maps drawn up to account for shifts in population following the 2010 census violated their voting rights. Republicans controlled all of Wisconsin's government after the last census and used their majorities to devise maps that greatly favored them.

Last year a panel of federal judges ruled 2-1 that the maps were drawn so favorably for Republicans that they violated the rights of Democratic voters in Wisconsin.

Beverly Speer of Madison, a member of Wisconsin Democracy Campaign, attends a rally Sunday evening at Plymouth Church in Milwaukee for the plaintiffs in Wisconsin's voter redistricting case.

Sachin Chheda, director of the Fair Elections Project, said the case is bipartisan and will help disenfranchised voters in other states including those where Republicans have been targeted by unfair district maps.

State Rep. Fred Kessler, a Democrat representing Milwaukee's 12th Assembly District, was part of a small group that met in Milwaukee in 2013 to discuss gerrymandering. Their discussion led to the lawsuit.

"I think we are going to win this," Kessler said as the crowd cheered. 

If the group of Democrats is successful before the nation's high court, all states must follow new rules on gerrymandering when they draw congressional and legislative maps following the next census in 2020. A decision is expected by next summer.

Attorneys handling the case for Wisconsin contend the test proposed by the Wisconsin Democratic plaintiffs is biased against Republicans because Democrats tend to congregate in cities like Madison and Milwaukee.

Donohue disagreed: "It's an argument, but not a persuasive one." She said her district "was so classically cracked," meaning it was redrawn to dilute the number of Democratic voters.