Democrats are worried their party unity is fraying five months out from the presidential election as several contested primaries pitting progressives against mainstream Democrats go down to the wire.
Some Democrats have begun pointing the finger at Sen. Bernie Sanders (I-Vt.), saying he's been consumed with down ballot elections at the expense of promoting Biden's bid for the White House.
The Democrats, who are not affiliated with the Biden campaign, say Sanders needs to do more to make sure progressives fall in line behind Joe Biden in November.
While they concede Sanders has done more to help Biden than he did in the 2016 race for then-Democratic nominee Hillary Clinton, they still say Sanders needs to use his influence with his supporters to ensure they turn out, as well as donate to Biden's campaign.