I'm under the impression that there's a faction within the Democrats who support Bernie Sanders and Elizabeth Warren's leftist social programs, while others see those programs as completely implausible.
I'm under the impression, judging from the early debates, that the majority of democratic candidates are willing to offer much more open immigration, combined with socialized healthcare and welfare programs that cover those immigrants. Whereas, moderate Democrats, including Obama and Clinton, would never have supported this.
I'm under the impression that there's a faction of Democrats who believe that Joe Biden's seniority and centrism gives the party a chance to contend with Trump, while others feel he's "too old," "too white," and "not woke enough," meaning he doesn't give the party an identity they believe in.
No, I don't think the Democrats are unified right now. They need to find a strong, unifying candidate, they need to find common ground within the party, and their proposals have to be viable. Even so, they could do all of this and still lose to Trump in 2020.