May 18, 2021 12:07 PM Politicians will be able to make sure that some of the purplest congressional districts in the U.S. donât stay that way. Bloomberg Governmentâs Greg Giroux examined district-by-district 2020 presidential election results and identified where the outcomes were the tightest. As youâll see in his chart, nonpartisan commissions will be the primary decision-makers on revising only three of the 10 congressional districts with the tightest top-of-the-ticket results. For the rest, including a district in Missouri where only about 100 votes divided the major-party presidential candidates, either legislatures will handle redistricting start to finish or the lawmakers have the power to ignore whateverâs recommended by independent commissions.