https://fivethirtyeight.com/features/dissecting-trumps-most-rabid-online-following/?ex_cid=538twitter

Editor’s note: The story below contains two slurs that appear in the names of subreddits. Links to Reddit may also contain offensive material.

President Donald Trump’s administration, in its turbulent first months, has drawn fire from both the left and the right, including the ACLU , government ethics accountability groups and former Bush administration officials . But one group has shown nothing but unbridled enthusiasm for the president’s actions thus far: the over 380,000 members of r/The_Donald , one of the thousands of comment boards on Reddit, the fifth-most-popular website in the U.S.

The subreddit, where posters refer to President Trump as the “ God Emperor ” and “ daddy ,” is arguably the epicenter of Trump fervor on the internet. Its membership has grown steadily since the 2016 presidential election, though its members were especially active during the campaign. They mobilized to comb through the hacked Democratic National Committee emails published on WikiLeaks and played a large role in spreading information and theories about those emails. More broadly, they waged the “ Great Meme War ”: an effort to get Trump elected by bombarding the internet with social-media-ready content promoting Trump or bashing Democratic candidate Hillary Clinton. Some of those memes played on Clinton’s campaign gaffes , such as her use of the phrase “ basket of deplorables ,” while others involved an emerging pro-Trump iconography centered around images of Pepe the Frog — a cartoon character with a convoluted history that gained especial prominence after it was co-opted by white nationalists as a sort of unofficial mascot . Members of r/The_Donald like to say they “ shitposted ” Donald Trump into office; regardless of whether the flood of memes swung the election, it did overwhelm the front page of Reddit to such an extent that the site’s CEO rushed to deploy a change in Reddit’s algorithm that limits the influence of any single subreddit.

What can we say about the animating force behind r/The_Donald? For one, it’s not universal among Trump supporters; nearly 63 million Americans voted for Trump, and the 382,000 members of r/The_Donald represent less than 1 percent of that. But in the subreddit’s vocal and dedicated membership, you can find an influential strain of Trump boosterism. According to former staffers , the Trump campaign team monitored the subreddit for messages that resonated, and Trump himself participated in an “Ask Me Anything” on r/The_Donald in July. Since the election, the subreddit has continued to serve as a conduit through which fringe conspiracy theories — often started on sites like 4chan.org, a freewheeling image-based message board best known for creating memes, posting stolen celebrity nudes and birthing the hacker collective Anonymous — enter a larger online discourse. The most striking example has been “Pizzagate,” the false idea that a pizza parlor in Washington, D.C., is the center of a child-trafficking ring involving Clinton campaign manager John Podesta, which prompted a man from North Carolina to “self-investigate” the shop, where he fired a rifle several times and threatened an employee.

r/The_Donald has repeatedly been accused of offering a safe harbor where racists and white nationalists can congregate and express their views, much the same way that Trump’s campaign is said to have mobilized and emboldened those same groups . And indeed, r/The_Donald is home to some pretty vile comment threads . The subreddit’s moderators declined to talk to us about their community and accused FiveThirtyEight of being “fake news.” Regardless, we think there’s a way to get at the nature of r/The_Donald that is more rigorous than doing a quick scan of its comments (and certainly more objective than simply soliciting the opinions of the group’s fans and detractors).

We’ve adapted a technique that’s used in machine learning research — called latent semantic analysis — to characterize 50,323 active subreddits based on 1.4 billion comments posted from Jan. 1, 2015, to Dec. 31, 2016, in a way that allows us to quantify how similar in essence one subreddit is to another. At its heart, the analysis is based on commenter overlap: Two subreddits are deemed more similar if many commenters have posted often to both. This also makes it possible to do what we call “subreddit algebra”: adding one subreddit to another and seeing if the result resembles some third subreddit, or subtracting out a component of one subreddit’s character and seeing what’s left. (There’s a detailed explanation of how this analysis works at the bottom of the article).

Here’s a simple example: Using our technique, you can add the primary subreddit for talking about the NBA ( r/nba ) to the main subreddit for the state of Minnesota ( r/minnesota ) and the closest result is r/timberwolves , the subreddit dedicated to Minnesota’s pro basketball team. Similarly, you can take r/nba and subtract r/sports , and the result is r/Sneakers , a subreddit dedicated to the sneaker culture that is a prominent non-sport component of NBA fandom.

This may all seem pretty abstract, but that same algebra can be applied to r/The_Donald. What happens when you break r/The_Donald up into subgroups using subreddit subtraction? What happens when you add unrelated subreddits to r/The_Donald? Before we get into those questions, let’s take a look at the subreddits that are most similar to r/The_Donald, according to our analysis :