According to writing that he left online, the apparent perpetrator of last Friday’s massacre at two mosques in New Zealand believes that the white race and Western civilization are under threat from immigration, particularly Muslim immigration. In the wake of the attack, it’s been pointed out that this belief about “the West” is shared by some of Donald Trump’s biggest online supporters and has been espoused to varying degrees of explicitness by Trump and his advisers themselves.

On Monday, Trump wrote on Twitter that the implication that he thus deserves blame for the mosque killings is “So Ridiculous” (random capitalization his). While it might be unfair to blame even the worst politicians for many radical acts of terror, in Trump’s case, his engagement with online extremists and promotion of their white-nationalist talking points does make the connection stronger—a reality underlined by the fact that, when I went to check on some of the more infamous white nationalism–adjacent accounts that Trump and his son Don Jr. have engaged with since launching his presidential campaign, I found that a number of them have been suspended by Twitter. (You can’t tell from looking at a suspended account why it was shut down, but “abusive behavior” is one of the things you can get kicked off for. Also, for the record, I’m using the term “white nationalist” here because of its political connotation—the belief that it’s acceptable for a country to define itself in racial terms. Obviously that idea also often corresponds with a belief in white racial superiority that you could describe as “white supremacist.”)

These accounts include:

• @whitegenocidetm, the anonymous Twitter user who made a joke about Jeb Bush that then-candidate Trump retweeted in January 2016. (“White genocide” is the far right’s term for the left’s alleged goal of replacing white populations with non-white ones through immigration.)

• @neilturner_, whose Twitter bio (per Politico) included the phrase “#WhiteGenocide is real,” and who Trump @’d or retweeted six times during the 2016 primaries.

• @keksec_org, an account whose archived tweets include racial slurs and race-war rhetoric and who Trump retweeted five times. (According to the Hill, @keksec_org also tweeted frequently about the alleged unique attractiveness of white women.)

More prominently, there’s Jayda Fransen, a far-right British politician who was publicly kicked off Twitter not long after Trump retweeted three hoax videos from her account that purported to show Muslims engaging in violence against whites. (Fransen’s fringe party, in the description of the New York Times, believes that “white Christian civilization is under threat from Muslims.”)

There’s also Milo Yiannopoulos, the former Breitbart writer who has been revealed to have solicited input on Breitbart stories from self-avowed white nationalists (including the proprietor of a neo-Nazi site called the Daily Stormer) and was booted from Twitter for inciting harassment against black actress Leslie Jones. Trump never retweeted Yiannopoulos’ account per se, so I didn’t count him for purposes of the headline, but he did take a question from Yiannopoulos during a campaign Reddit Q&A and promoted him by name on Twitter after taking office. As a candidate, Trump also infamously retweeted a fake graphic about black crime and an anti-Semitic Star of David image from accounts that appear to have been self-deactivated.

Trump Jr., meanwhile, has been caught following (or “caught,” because maybe he doesn’t care who knows it) at least three openly racist and/or anti-Semitic accounts—a writer named Vox Day, a notorious far-right figure who goes by the anonymous handle “Ricky Vaughn,” and a random racist with the handle AdolfJoeBidenTM—that are now suspended.

And this all on a service that has frequently come under criticism for being too hesitant to suspend or ban white supremacists. All in all, you might say that it is not “So Ridiculous” at all to suggest that Donald Trump has encouraged the online white-nationalist community and its most hateful behavior.