In the Democratic presidential primary, a great many pixels were spilled over the "Bernie Bros." This is Bernie Sanders' supposed army of young white male misogynists, patrolling the internet for any sign of women supporting Hillary Clinton, who they then harassed without mercy or quarter. But if Clinton voters thought the bros were bad, wait till they meet the Trumpists.
Of course, it's hard to say anything about one online community or another with ironclad certainty, given the lack of reliable statistics. The only actual survey I've seen about online abuse by 2016 candidates is from a consulting firm that put together a survey of 1,007 people over 18. It's not peer-reviewed or published anywhere except online, but it's as good as we're likely to get for the time being. Fifty-seven percent of respondents found Donald Trump supporters to be "very aggressive," as compared to 30 percent for Clinton and 16 percent for Sanders.
If that's not enough, just look around. Many liberals don't have that much experience with Trumpists, since so far they have mostly focused their fire on Trump's most immediate opponents: other conservatives.
So take a peek into the Twitter mentions of Red State's Ben Howe, who declared for Clinton now that Trump has secured the nomination — or the signature Trumpist hashtag, which is a more-or-less explicitly white nationalist slogan. You'll find a sewer of outright bigotry, genocide jokes, misogyny, oh and David Duke.
Better yet, look at Jewish conservatives like Ben Shapiro or Bill Kristol, who are under a constant deluge of bigoted abuse — and not just on social media, but from major pro-Trump writers and publications. (Breitbart, which has been pro-Trump to the point of siding with him against one of their own writers who was allegedly attacked by Trump's then-campaign manager, recently published an article about how Kristol is a "renegade Jew.") Some are already constructing a new Dolchstoss Legende blaming American Jews for Trump's possible election defeat in November.
In this Trumpists take their cue from Trump himself, who has campaigned on open bigotry, repeatedly incited violence against anti-Trump protesters, and otherwise followed the incipient fascist playbook almost to the letter. Most recently, he refused to condemn his supporters' anti-Semitic harassment of reporter Julia Ioffe, who wrote a profile of his wife (or as the white supremacist site Daily Stormer calls her, "Empress Melania").
To my mind this is the worst aspect of Trump's rise. Republicans playing footsie with racist white people to get votes is sadly nothing new. But running a major party campaign about as prejudiced as that of Strom Thurmond in 1948 is something new — particularly when the overall trend had been in the opposite direction. Anti-Semitism used to be political poison, but Trump is bringing it back at least adjacent to the mainstream. It's no coincidence white supremacists are besides themselves with glee over Trump.
All this is not to say that there is no trace of prejudice on the American left (from liberals to leftists), or that it's not important to address that when it does crop up. But Trump and his supporters are a fundamental threat to the basic norms that have underpinned American politics for the past half-century. Unlike the leftists backing Sanders, the alt-right crowd supporting Trump does not care a whit for people calling them bigoted. On the contrary, they revel in it.