WSJ/NBC Poll - Hypothetical head-to-head 2020 match-ups:

Biden 51 - Trump 42
Sanders 50 - Trump 43
Warren 48 - Trump 43
Harris 45 - Trump 44

Trump approval at 45-52, meaning that even against the more unknown candidates he can't even pull his approval in a head-to-head match-up

— The Darkest Timeline Numbersmuncher (@NumbersMuncher) July 14, 2019