New Iowa poll shows Warren, Buttigieg gaining on Biden

A new poll from the Des Moines Register show Joe Biden still leading the crowded 2020 Democratic field, but by a slimmer margin. Meanwhile, Sen. Elizabeth Warren and Mayor Pete Buttigieg are now both in double digits. CBSN political reporter Caitlin Huey-Burns and the Washington Post’s Amber Phillips join CBSN’s “Red & Blue” to discuss the latest on the campaign trail. Source