NASHVILLE, Tenn. -- Republican lawmakers in Tennessee are poised to take up a plan Thursday that could carve up a majority-Black congressional district, reshaping it to the GOP's advantage as part of President Donald Trump's strategy to try to hold on to a slim House majority in the November midterm elections. The redistricting effort in Tennessee is one of several rapidly advancing plans in Southern states as Republicans try to leverage a U.S. Supreme Court ruling that weakened the federal Voting Rights Act. The court ruled that Louisiana relied too heavily on race when creating a second Black-majority House district as it attempted to comply with the federal law. The high court's decision altered a decades-old understanding of the law, giving Republicans grounds to try to eliminate majority-Black districts that have elected Democrats. Louisiana has postponed its congressional primary to give time for state lawmakers to craft a new House map.…