Since the most action during primary season was on the Republican side, we didn't hear much about the cracks that were already beginning to split apart the Democrat coalition, which has now turned into a full-on civil war.
The parallels drawn between the Bernie movement and the Trump movement focused mostly on their being anti-Establishment and oriented toward economic populism rather than the usual topics. That made it clear that the Left populists were breaking away from the mainstream of their party, but there was actually a far broader range of reliable Democrats who were starting to get fed up with the direction of their party toward identity politics uber alles.
Not conservative Democrats, who have already switched over to Republican or not involved.
They're not even moderates on social-cultural issues -- they support gay marriage, they hate religion, and they want increased gun control. They make a point of saying that racism, sexism, etc. exist, and that we should call it out and shame people for it.
Their distinguishing traits are atheism and skepticism, which doesn't mean that's their main cause, only that it separates them from other liberals. Stressing reason, logic, and facts, they bristle at identity politics, which stresses unthinking tribalism, airing of grievances rather than productive debates, and generally a more emotionalist approach to politics. It rejects the obsession with victimhood and oppression, and takes a more constructive engineering approach to fixing problems.
Demographically, they're mostly white, educated, under-40, living in major metro areas, both male and female. In other words, like the populist and environmentalist progs who supported Bernie in such large numbers. Sure enough, most of these non-progs were big on Bernie, too, even if they didn't care what the TPP was all about.
Bernie was not speaking to their major concerns -- boo religion, yay gays, etc. Of the economic topics he focused on, probably the only one that really got their attention was student debt. It was simply the fact that he wasn't making an emotional appeal to tribal identity (race, sex, or whatever), nor trying to win by having the biggest chip on his shoulder.
As an example, consider YouTuber Jaclyn Glenn, who has half a million subscribers, along with 100K each on Twitter and Instagram -- someone who resonates with enough people to make it worth studying just one person's output. And her videos go back to 2010, so there's plenty to study about how she has changed.
She's an early Millennial, college-educated, female, atheist, pro-gay, crazy cat lady, transplant to Los Angeles. Aside from being white, she checks the boxes for being a loyal Democrat. Sure enough, lots of her videos focus on how stupid, evil, etc., Republican voters and politicians are. Going through the titles of videos in her archive, and listening to a random sample, it was the same ol' predictable crap that you'd expect from her demographic background in the political scene of the 2010s.
In 2014, she did express exasperation at how easily offended the third-wave feminists were, but she didn't really stick with this, or turn against feminist identity politics per se. Just, "Wow, settle down -- we're fighting for the same thing ultimately."
On her twitter the term "feminists" shows up a few times in 2014, provoked by GamerGate. She was against the feminazis like Anita Sarkeesian, but also not on board with the anti-feminists. That was the first major time when she felt like there was no middle ground, and you had to pick which side you were on. GamerGate may have opened up young people not only to the future Alt-Right, but also to the future "Shut it, feminazis" strain within the Bernie movement.
That disappeared once the controversy died down by the end of 2014. It's not until primary season began late last year that she really starts sounding off against the identity politics mainstream of her party. The Democrat civil war was just warming up.
Here is her response to the Islamic terrorist attacks in Paris. She all but says, "Hey Trump may have a point with his Muslim ban." It's not being an atheist that primes her to say that, since plenty of atheists apologize for Islamic terrorism. She knows they're the only ones who do this shit (despite a half-hearted reference to the Christian crusades nearly 1000 years ago). There's no room in the Democrat mainstream today for someone who is unapologetic about the danger that Islam uniquely poses to us here and now, and the need to do something about it.
Here is her explicit rejection of feminist identity politics, surrounding the denunciations by older feminazi types that women must vote for other women, or otherwise behave as mere drones in a hive serving the queen bee (that bitch). Wearing a Bernie t-shirt.
Here is an even better rejection of identity politics, reacting to some uppity black girl SJW whining about white privilege, and trying to shame white women for even having to ask what it is, as though they deserved an answer. (The uppity SJW actually demands that white women allies ought to pay her for droppin' dat knowledge on dere melanin-deficient ass.) Her response is pretty angry for a supposed ally. Sounds like she's this close to saying, "Well we don't need you dumb ghetto trash anyway."
Here she is parodying a hardline feminazi while interviewing pedestrians about inane SJW crap at Venice Beach of all places, underscoring what party-poopers the feminists are. During the past couple months, she's put out quite a few of these anti-feminazi videos.
Here is her "get over it" message to all of the #NotMyPresident complainers (she voted Hillary, too). And she was the one who made that not-really-anti Trump song during the summer, "Hump Trump". She isn't freaking out about his election bringing about the apocalypse, even if she doesn't like where it'll go.
The situation looks dire if the Democrat leadership can't even hold onto someone who was a stereotypical Democrat before primary season. She's not a populist / anti-war activist, showing that the Sanders supporters were drawing more broadly than just the progs. But she's not a rabid SJW or bound by the spell of tribal identity politics, so how can she still be a reliable Democrat?
Of course, she's not going to defect to the other side (unless she marries a Trump supporter). But the intense dissatisfaction with the party leadership means a deeply divided party for the foreseeable future.