Rep. Bob Onder of Missouri has filed a lawsuit in federal court seeking to overturn a decision by the Missouri Supreme Court that blocked a Republican-friendly congressional map from being used in the upcoming midterm elections. The lawsuit, filed Friday, contends the state court’s ruling violates both the U.S. and Missouri constitutions.

Onder, along with Republican House candidate Rick Brattin and two Missouri voters, argues that reverting to the old district lines for the November election is impractical and would cause significant confusion and hardship for voters, candidates, and election administrators. The congressman characterized the state Supreme Court’s action as an “unprecedented” and “startling act of judicial supremacy” that disregarded the votes of 1.2 million primary voters who had already chosen their general election candidates.

"After 1.2 million primary voters in Missouri had chosen their candidates – Republican and Democrat and Libertarian and Green — for the general election," Onder said in an interview. "In doing so, they effectively disenfranchised 1.2 million Missourians."

The Missouri Supreme Court’s unanimous decision last Thursday ordered a statewide referendum in November to determine the fate of the new map. The court blocked the districts, which had been used in the state’s August primaries, following the submission of petition signatures that called for a statewide vote on the map. This new map was designed to give Republicans an advantage in the House seat for which Brattin is running, a seat currently held by a Democrat.

"Primary voters chose the Republican and the Democrat nominee, and all of a sudden you’re just going to scramble those various nominees and have them run in different districts? It just makes utterly no sense whatsoever," Onder stated. He expressed concern from constituents who were anticipating elections based on the primaries they had already voted in.

Missouri Republicans are also seeking intervention from the U.S. Supreme Court. Missouri Attorney General Catherine Hanaway announced Friday evening that an emergency application had been filed with the high court, stating, “We look forward to [the US Supreme Court’s] prompt review of this critical matter, as our ability to hold timely and lawful congressional elections hangs in the balance.”

Onder cited a history of legal precedent against altering election maps close to Election Day, especially after primary elections have concluded. Both the state and federal courts were expected to receive arguments from both sides by Monday.