This week Joe Biden from Sen.
Bernie Sanders, Barack Obama, and Elizabeth Warren.
But, will that be enough to help him?
CNN reports that Biden is lagging in support from young voters.
Sanders and Obama are popular among young voters.
At this point Biden is underperforming 2016 Democratic presidential nominee Hillary Clinton with younger voters.
According to 2016 pre-election polling leading up to election day Clinton led among 18-34 year-olds by a 22-point margin.