Breaking News EmailsGet breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings.SUBSCRIBEJan. 4, 2019, 7:20 PM UTC / Updated Dec. 3, 2019, 6:31 PM UTCBy Liz Johnstone and Jeremia KimelmanFirst it was challengers “taking a look at,” “thinking about” and “not ruling out” a White House bid. Now the field of people who want President Donald Trump's job is at the start of its inevitable shrinkage.Here’s a timeline of the Democratic presidential candidate field.Follow our 2020 election coverage here.Liz JohnstoneLiz Johnstone is a politics editor for NBC News. Jeremia KimelmanJeremia Kimelman is an interactive graphics developer for NBC News.Joe Murphy contributed.