One can draw too many inferences from a life spent online, but I see a lot of antagonism towards The Left, and by The Left I just mean people who, before the whole Clinton/Sanders spat erupted, were pretty solidly in the mainstream of the online Left, a group which was the on the left wing of the democratic party, but not exactly planning on leading the communist revolution. Policy positions that I thought were pretty standard fare are now dismissed because they're associated with Sanders, and therefore associated with Berniebros, and therefore the people who didn't vote for Hillary Clinton and therefore the people who are to blame for all of this. There are a lot of assumptions in there (and of course I'm making gross generalizations I recognize), as on the internet no one knows you're a dog. But basically there's a chain of them which goes from support of policy ideas which were pretty standard stuff before the primary means you didn't vote for Clinton which means it's all your fault.
I don't have much patience for lefties who pay enough attention to politics to argue about it online and who chose not to vote for Clinton, but I also know a lot of people who are lefties, did support Sanders, did support Clinton after the primary was over, did tell other people to vote for her, and did (they say) vote for her, who get a lot of shit because reasons I haven't yet figured out. Basically, shutup you supported Sanders! I mean, hate Bernie if you want, but getting mad at people who voted for him and then going on to dismiss a political agenda because it's associated with him is pretty weird. I see a lot flaming liberals now sounding like Max Baucus for reasons I don't quite understand. I'm not a "Bernie would have won" guy and I tend not to put much stock in any monocausal explanations for a lost close election, but I suspect the doubling down on what Washington perceives as centrism (but which isn't meaningfully "centrism") isn't really the way to go.*
Yes there be assholes on the internet, but the actual primary as waged between the campaigns of Hillary Clinton and Bernie Sanders was the gentlest most mildly "fought" presidential primary contest I've ever seen. Clinton and Obama were assholes to to each other in 2008, everyone was assholes to everybody in 2004, and Gore and Bradley (remember him?) were assholes to each other in 2000.
*This is too much for this blog post, but here's where people chime in and say "Hillary Clinton had the most progressive platform ever!" That's true enough, but Clinton also has a long history, a long set of associations, a voting record, a record of public statements,and ran a campaign which explicitly and implicitly rested on continuing the Obama agenda. I'm no Obama hater, either, but he also explicitly embraced the identity of the left leaning version of centrism. I'm aware that in 2008 plenty of people hoped (hah) and believed that Obama was secretly a lot more liberal than his campaign suggested, but anyone who paid attention knew that the campaign as staged was basically between two centrists.
Democratic centrism isn't the same as Republican centrism. It's better! For example, it isn't true that Obamacare is just the Heritage Foundation health care plan. It's better! But it's still based on the same blueprint. It's still deep in the ideology of centrism which still only flirts with more solid Lefty positions. Democratic centrism still doesn't see that things are fucked up and bullshit, and going on 40 years of ideological centrism has been the problem, not the solution. It still laughs at those crazy lefties and their "unicorn" ideas. It still sees centrism as both the only achievable thing (perhaps true!) and the only politically popular thing (likely not true!). It's still an ideology which sees that political wisdom is found in talking to Joe Klein, David Brooks, and Tom Friedman. It's politics that sees winning elections as winning over the Charlie Rose Green room while signalling some cultural affiliations with the rubes in Fritters every four years.