(John Amis | AP) Democratic presidential candidates from left, Sen. Cory Booker, D-N.J., Rep. Tulsi Gabbard, D-Hawaii, Sen. Amy Klobuchar, D-Minn., South Bend, Ind., Mayor Pete Buttigieg, Sen. Elizabeth Warren, D-Mass., former Vice President Joe Biden, Sen. Bernie Sanders, I-Vt., Sen. Kamala Harris, D-Calif., former technology executive Andrew Yang and investor Tom Steyer wave to the audience before a Democratic presidential primary debate, Wednesday, Nov. 20, 2019, in Atlanta.