After Missouri lawmakers finished drawing new congressional district boundaries last year, St. Louis Democrats William "Lacy" Clay and Russ Carnahan were moved into the same district.
And the two St. Louis area incumbents now facing each other for the 1st District seat are on opposite sides of the court battle over that congressional map - a battle that's waiting for a ruling from the Missouri Supreme Court.
Carnahan's current 3rd District runs from the south part of St. Louis City, south through a portion of St. Louis County and all of Jefferson and Ste. Genevieve counties, but a new 3rd District has been drawn around the St. Louis area, which extends west to include Cole, Osage and Miller counties, and a part of Camden County, in Mid-Missouri.