NPR's Scott Detrow reports on the ongoing legal battle over Missouri's congressional redistricting map, which could flip a House seat to the Republicans. A federal appeals court ruled that the GOP-backed map should be used for the midterms, overriding a state supreme court decision that favored the existing Democratic-leaning map. The dispute centers on whether primary voters' rights are protected by using the map from the August primaries, with ballots already mailed out. Legal experts expect the case to return to the U.S. Supreme Court, which has previously declined to intervene but may r…