>> "all in" starts now. good evening from washington, d.c. i'm joy reid in for chris hayes. tonight we are learning more about who won last night's democratic presidential debate. at least according to early polling. finding that elizabeth warren was the clearest overall winner and the only candidate among the top four who emerged with more democrats considering voting for her. the polling also found mostly good news for pete buttigieg, cory booker, andrew yang, amy klobuchar and beto o'rourke. who in front of the eyes of the nation and in the wake of a pair of deadly mass shootings in his home state of texas seemed to shift the terms of the gun safety debate in america. >> in odessa i met the mother of a 15-year-old girl who was shot by an ar-15, and that mother watched her bleed to death over the course of an hour because so many other people were shot by that ar-15 in odessa and