Even before the 2020 Democratic debates have begun, we’re already starting to get a sense of who the top candidates are. Former Vice President Joe Biden, Sen. Bernie Sanders, I-Vt., Sen. Kamala Harris, D-Calif., Sen. Elizabeth Warren, D-Mass., and even South Bend, Ind., Mayor Pete Buttigieg all look like formidable potential challengers to President Trump.

Then there’s Cory Booker.