By the next morning, the hashtag — #MayorCheat — was trending worldwide.
“That’s so funny that we’re the first people to make this joke,” said Nick Thorburn, a 38-year-old musician.
Not everyone was laughing.
Some on social media capitalized on the trending hashtag to spread misinformation or conspiracy theories about Buttigieg, including claims that he had colluded with the Democratic Party to rig the caucuses. Other accounts accused Russian trolls of promoting the hashtag to divide Democrats.
Yet it wasn't the work of Russian trolls, or even Republican pranksters.
The inaccurate insults were traded online among fellow Democrats. And it's the type of left-wing misinformation that, combined with a prolonged primary contest, has some worried about the party's ability to unite ahead of November.
“I hope people, if their candidate doesn't get the nomination, can still support whoever does,” said Gary Klar, a retired school teacher from Hancock, N.H. who supports Joe Biden but said he will vote for whoever wins the party's nomination. “We don't want sour grapes.”
As the tight race moves on to Nevada and South Carolina, the online misinformation has not died down. Unsupported claims making the rounds in recent days include assertions that one Democratic candidate has a history of heart attacks and that another killed dogs as a child.
Propagating an online smear against a rival requires only coining a snappy hashtag, creating a satirical meme or simply stating the threads of a conspiracy theory. Those tactics are the new normal in political campaigning, explained Susan Etlinger, an industry analyst for Altimeter, which researches and advises on disruptive technologies.
“Anybody with an agenda, a little bit of a budget and some time can figure out a way to troll, to create a bot or to use cheap fakes,” said Etlinger, referring to automated accounts and manipulated images. “We’re entering this phase now that we have to take for a given that for any election ... there’s a potential for a lot of misinformation.”
The Democratic infighting echoes 2016, when supporters of Vermont Sen. Bernie Sanders accused the Democratic Party of favoring the eventual nominee, Hillary Clinton. Many Sanders supporters were suspicious of party insiders and news outlets that they believed unfairly boosted Clinton, said Pat Cote, a Sanders supporter.
Cote said he now tweets several times a day about Sanders, his rivals or the election.
Earlier this week, he tweeted to his 33,300 followers that the upcoming Nevada caucus is “going to be a disaster and nothing is being done to stop it. The only explanation is that this is done by design."
Cote said social media has emerged as a key way for Sanders supporters to organize and push back against what they see as an unfriendly establishment.
In the days that followed the Iowa caucuses, as the results remained in limbo, some progressive Twitter users claimed Buttigieg’s campaign had developed the failed app that was used to count the votes in Iowa. (It didn’t.) Others began posting images of rats that mentioned Buttigieg.
Republicans also got in on the action, promoting the idea that the Iowa results were tainted for the Democrats. Shortly after the Iowa Democratic Party announced it was reviewing results for “quality control,” Trump’s campaign manager Brad Parscale tweeted: “Quality control = rigged?”
Since then, the online tenor of the race has become a campaign talking point.
During Wednesday's Democratic debate in Nevada, Sen. Elizabeth Warren was asked whether such attacks from Sanders' supporters might make it difficult to unite the party. Warren last month found herself on the receiving end of online attacks when accounts claiming to support Sanders flooded Twitter with the snake emojis and the terms #NeverWarren and #WarrenIsASnake, after she claimed that Sanders had told her privately in 2018 that a woman could not win the presidency.
“Look, I have said many times before, we are all responsible for our supporters,” Warren said in response. "And we need to step up. That's what leadership is all about."
Sanders argued back that his own backers have been targeted with “vicious, racist, sexist attacks” and that most of his supporters don't send hateful messages online.
“We have over 10.6 million people on Twitter, and 99.9 percent of them are decent human beings, are working people, are people who believe in justice, compassion, and love,” he said. “And if there are a few people who make ugly remarks... I disown those people."
Mike Bloomberg’s campaign also released a campaign video Monday on Twitter criticizing “Bernie Bros.,” the nickname given to some of Sanders’ most vocal online supporters.
"We need to unite to defeat Trump in November. This type of ‘energy’ is not going to get us there," Michael Bloomberg wrote Monday in a tweet that accompanied the new campaign ad.
The nicknames and taunts that Sanders’ supporters hurl at rival campaigns is a familiar strategy, and one that Trump has successfully employed for years, said Rita Kirk, a political communication expert at Southern Methodist University.
During a contentious 2016 Republican primary, Trump branded GOP challengers Sen. Marco Rubio and Sen. Ted Cruz as “Lil’ Rubio” and “Lyin’ Ted,” respectively. Trump’s supporters often repeat the insults during chants at the president’s rallies or online.
Those jibes are meant to influence how voters view a candidate.
“Sanders’ demographic is young people who are super social media savvy and (to them) it’s just fun — they want to come up with the first trending statement,” Kirk said. “But it affects an image of that person, whether you like them or not.”
Seitz reported from Chicago.