This week the leftish Twittersphere and liberal comment sites went wild for two stories. The first, that President Donald Trump doesn't seem to know who Frederick Douglass was. The second, that those Berkeley students and non-Berkeley anarchists who shut down the Milo Yiannaopolous meeting might not have done such a bad thing. Okay, a mob silenced Milo, people tweeted and intoned, but perhaps that's okay in the anti-Trump fightback.

It's almost unbearably ironic. Because if these critics of Trump themselves knew anything about Douglass, they'd know he was implacably opposed to using mob pressure to shut down public meetings. They'd know he valued free speech so highly, above all other values, that he thought no one should ever be "overawed by force" simply for what he thinks and says. Imagine: in one breath mocking Trump for not knowing who Douglass was, and in the next saying things that will have made Douglass spin in his grave.

The mocking of Trump followed his comments marking Black History Month, on Wednesday morning. He praised Dr. Martin Luther King, Harriet Tubman, and Frederick Douglass, before going on to talk about matters closer to his heart: himself and how much he hates CNN.

But it seems he doesn't know much about Douglass, the slave turned abolitionist and suffrage campaigner who wrote brilliantly in defence of free speech and the right to bear arms. He was fleeting in his praise of Douglass, and his wording seemed to suggest he thinks Douglass is still alive (he died in 1895.)

The headlines and snark came flying. "Trump implied Frederick Douglass was alive," the Washington Post laughed. "Seth Meyers roasts Trump for being too lazy to Google whether Frederick Douglass is still alive," said a headline over a video of Seth Meyers doing exactly that. Cue millions of shares.

All of which is fine, of course, and funny in fact. Trump really ought to know about Douglass. Someone should have briefed him. But then the same political sphere that came over all pro-Douglass as a way of meming against the President—right-on tweeters, the left-leaning web—started to wonder out loud if it's such a bad thing that Milo was silenced at Berkeley. Which is about as anti-Douglass a thing as you could say.

"Milo Yiannopoulos is trying to convince colleges that hate speech is cool," CNN cried. When Trump tweeted that perhaps Berkeley should have its federal funding cut if it won't stand up for free speech, The Advocate accused him of "defending hate speech." The mayor of Berkeley, Jesse Arreguin, implicitly sided with the protesters against freedom of speech when he said: "Hate speech isn't welcome in our community." In short, let's cleanse Berkeley of certain, dangerous ideas; let's make it a Milo- and alt-right-free zone.

The celeb set also welcomed the shutting down of Milo's meet. "RESISTANCE WORKS!", tweeted Debra Messing. As Heat Street said, "vocal members of the progressive left took to social media" to celebrate Milo's silencing, "dubbing it a legitimate resistance movement against the Trump administration."

This cheering, or at least failure to challenge, the heavy-handed prevention of political chatter at Berkeley is a far bigger snub to Douglass and everything he stood for than Trump's Black History comments were. Indeed, anyone who knows anything about Douglass will know that one of the most stirring, moving things he ever wrote was a criticism of the shutting down of public meetings by mobs.

On 2 December 1860, at the Tremont Temple in Boston, anti-slavery activists held a meeting called "How Shall Slavery Be Abolished?". Douglass was there. To his horror, a group of pro-slavery people—Douglass called them "a mob of gentlemen"—disrupted the meeting. They screamed insults at the attendees, took over the room, drowned out anyone who tried to speak. They pushed the attendees about. Douglass was most alarmed by the failure of the mayor of Boston to protect the meeting. The gathering was "broken up and dispersed by the order of the mayor, who refused to protect it, though called upon to do so", he wrote. This brings to mind Mayor Arreguin's craven response to the Berkeley fiasco.

In response to this illiberal violence, Douglass wrote an article titled "A Plea for Free Speech in Boston." It is one of the best things ever written about free speech. He said the intrusion and stopping of the meeting was "a palpable and flagrant outrage on the right of speech." He said it had "trampled under foot" the "law of free speech and the law for the protection of public meetings." And then, in words that echo down the decades, he spelled out why freedom of speech is so important:

"Liberty is meaningless where the right to utter one's thoughts and opinions has ceased to exist. That, of all rights, is the dread of tyrants. It is the right which they first of all strike down. They know its power. Thrones, dominions, principalities, and powers, founded in injustice and wrong, are sure to tremble, if men are allowed to reason of righteousness, temperance, and of a judgment to come in their presence."

This is probably Douglass's most important legacy: his argument that free speech underpins all liberty; that the freedom to think and speak and organise is the precursor to any kind of progress. And it is this legacy that is shot down by those who argue that using pressure or threats or speech codes to shut down controversial speakers is acceptable behaviour.

Sure, the men meeting in Boston 150 years ago were discussing something incredibly important and good—how to abolish slavery—while Milo's meeting would largely have consisted of provocateur ridicule. But so what? As Douglass said in that article, all people, whatever their thoughts or station, should enjoy freedom of speech: "There can be no right of speech where any man, however lifted up, or however humble, however young, or however old, is overawed by force, and compelled to suppress his honest sentiments."

So yes, of course Trump should know who Douglass was—I hope someone has since given him a copy of Narrative of the Life of Frederick Douglass, Douglass's profound autobiography. But in continually compelling people to suppress their honest sentiments, in "overawing by force" those they disagree with, in thinking it is acceptable to use pressure or law or rules to prevent the holding of public meetings, too much of the modern left does an even greater disservice to Douglass. They forget his plea to humanity to remember that liberty is meaningless where people's right to utter their thoughts has ceased to exist.