U.S. Chief District Judge Chip Campbell on Thursday rejected Tennessee Democrats' request for a temporary restraining order to stop the state from implementing a new U.S. House map that favors Republicans. Why it matters: The legal challenges to the new map will press on, but Campbell's ruling is a critical setback for opponents. State of play: Democratic candidates, including U.S. Rep. Steve Cohen, state Rep. Justin Pearson and Columbia Mayor Chaz Molder, along with Tennessee voters, sued to s