Just two months ago, Missouri voters approved a constitutional amendment to change how the state draws legislative boundaries. The state’s lawmakers, who return to session this week, aren’t having it and may seek to nix or rewrite the anti-gerrymandering law.

Missouri was one of four states where voters last year decided to make significant changes to the redistricting process in the name of curbing partisanship and reducing political influence on legislative and congressional maps.

In approving a measure known as Amendment 1 with more than 60 percent of the vote, Missouri voters chose to give much of the power to draw state House and Senate districts over to a demographer who must craft a map that emphasizes partisan fairness and competitiveness.

Before passage of Amendment 1, which also included curbs on lobbyist-paid gifts and making legislative emails open records, a panel split evenly between Republicans and Democrats, not lawmakers themselves, was tasked with drawing House and Senate maps (although courts frequently stepped in to complete the maps if the panel was deadlocked).