Five people were arrested Friday night, and two officers were injured in skirmishes that broke out after Donald Trump abruptly canceled a Chicago rally on Friday. And Donald Trump had no doubts about who was to blame for the shocking violence: organized “thugs.” Trump tweeted on Saturday: “The organized group of people, many of them thugs, who shut down our First Amendment rights in Chicago, have totally energized America!”

Rivals quickly pointed the finger at Trump though, saying that the violence at his rallies reflect the tenor of the front-runner’s campaign. “A campaign bears responsibility for creating an environment,” said Ted Cruz. “The predictable consequence of [Trump’s comments] is it escalates. Today is unlikely to be the last such instance.” John Kasich also criticized Trump along the same lines: “Tonight the seeds of division that Donald Trump has been sowing this whole campaign finally bore fruit, and it was ugly.”

The organized group of people, many of them thugs, who shut down our First Amendment rights in Chicago, have totally energized America! — Donald J. Trump (@realDonaldTrump) March 12, 2016

Sen. Bernie Sanders also got in the game and tweeted a thinly veiled shot at Trump:

We do things a little different in this campaign: We bring people TOGETHER. #BernieInIL — Bernie Sanders (@BernieSanders) March 12, 2016

But you hardly need to be a Trump rival to see the connection between his campaign for the presidency and violence. Some are even surprised this kind of violence didn’t happen sooner. The Associated Press explains:

Since casting Mexicans immigrants as rapists and criminals in his June announcement speech, Trump has encouraged supporters to embrace anger tinged with xenophobia. In recent weeks, his rallies have featured several minor incidents of violence involving protesters, almost all of them minorities, with Trump repeatedly encouraging his supporters to fight back—and to do so with violence if necessary.

The Los Angeles Times agrees nothing about the violence is surprising:

What many had feared as Trump’s campaign has proceeded had finally happened on a large scale: A flammable brew of populist anger, campaign mismanagement, a candidate’s own provocative encouragement and protesters fighting back — quite literally — finally found its fuse. The explosion was predictable, given tensions in the country around its changing demographic face and economic displacement that has left many fearful and upset, receptive audiences for Trump’s surprisingly strong candidacy.

The violence at the canceled rally came on the same day as Trump had been calling on the Republican Party to unite behind his candidacy.

Read more Slate coverage of the GOP primary.