McCain is almost equally unpopular with Republicans (35 percent approve; 55 percent disapprove), Democrats (29 percent-53 percent) and independents (25 percent-55 percent). In hypothetical 2016 reelection match-ups, McCain trails both former Surgeon General Richard Carmona, who ran against McCain's junior colleague Jeff Flake in 2012, and former Rep. Gabby Giffords.