The claim that Khalil was “mobilizing support for Hamas” hasn’t been backed up by any meaningful evidence. Trump and his cronies (and indeed many Democrats) often use “pro-Hamas” as an all-purpose smear against anyone who protests Israel’s genocidal war in Gaza, just as protesters against the war in Iraq were once smeared as “pro-Saddam.” It doesn’t matter how critical we are of Hamas itself — if you’re against Israel’s cruel bombardment of Gaza’s civilian population, you’re a Hamas sympathizer.

Vague rumors have circulated about “pro-Hamas brochures” Khalil was allegedly involved in distributing, but so far I’ve seen neither a concrete example of what was in any such brochure nor evidence of Khalil distributing it. Similarly, no one has coughed up any evidence of Khalil saying or doing anything antisemitic — at least insofar as that term designates ethnic or religious prejudice against Jews. The accusation makes a lot more sense once you realize that the US State Department has officially adopted a definition of antisemitism so absurdly broad and politicized that it explicitly includes political opposition to Zionism (“denying the Jewish people their right to self-determination”) or even “applying double standards” to Israel and other states.

The Democratic minority leader in the Senate, Chuck Schumer, simply accepted the Trump administration’s characterization of Khalil as fact. In a profoundly underwhelming social media post, where actual criticism of the arrest was so muted you could blink and miss it, Schumer smeared the student protests at Columbia as “anti-Semitic actions,” never mind that a great many of the student protesters were themselves Jewish. At the end of two paragraphs of hedging, Schumer said that “if” the administration can’t prove that Khalil committed serious crimes and hence wants to deport him for his politics, “then that is wrong” and a violation of the First Amendment. His counterpart in the House, Hakeem Jeffries, issued a statement that was almost identical.

Meanwhile, the Trump administration has never bothered pretending that Khalil was being targeted for any reason other than the content of his constitutionally protected political speech. Days before Schumer dropped his master class in saying as little as possible with as many words as possible, Secretary of State Marco Rubio baldly announced that all other “Hamas supporters” with green cards would be deported along with Khalil. The president himself ranted on Truth Social on Monday that “pro-terrorist, anti-Semitic, anti-American activity” (i.e., student protests against the bombing of Gaza) won’t be “tolerated” by his administration. As I discussed elsewhere, his statement left little doubt that if he thought the courts would let him get away with arresting citizens who participated in the protests, he’d do that too.

The congressional left, to its credit, has been clear on the core of the issue. For example, Congresswoman Rashida Tlaib has said, “Criminalizing dissent is an assault on our First Amendment and freedom of speech. Revoking someone’s green card for expressing their political opinion is illegal. Protesting genocide is not a crime.”

Tlaib and thirteen other Democratic lawmakers (Ilhan Ohmar, Mark Pocan, Nydia Velázquez, Delia Ramirez, Jasmine Crockett, Summer Lee, Ayanna Pressley, Lateefah Simon, Gwen Moore, Nikema Williams, Al Green, André Carson, and James McGovern) signed an open letter calling Khalil a “political prisoner” and calling for his immediate release. The failure of the great bulk of mainstream Democrats to join them is shameful.

As of yet, there’s no evidence that Khalil supported Hamas. And even if he had, the “political prisoner” designation would still be straightforwardly correct. Here’s an easy way of seeing that point: If a pro-Palestinian administration were in office, would they be justified in arresting and deporting Columbia professor Shai Davidai? An Israeli citizen with a green card, Davidai has spent the last year and a half denouncing the protests, calling for repression against them, and justifying Israel’s action in Gaza.

As Rosa Luxemburg once put it, “Freedom is always and exclusively for the one who thinks differently.” In other words, everyone supports free speech for people whose views they accept. The test of our commitment to free speech is always whether we extend that conviction to people whose views we abhor. The Republican Party and parts of the pro-Israel Democratic Party have failed that test.

Every year for the last quarter of a century, Gallup has asked Americans, “In the Middle East situation, are your sympathies more with the Israelis or more with the Palestinians?” This year, only 46 percent said “the Israelis.” That’s an all-time low. And the number who say “the Palestinians” is at an all-time high of 33 percent.

On one level, those should be sobering figures for those of us who care about Palestinian rights. Even after a year and a half of atrocities on a scale every significant human rights organization has called “genocidal,” we’re still very far from having won the war for Americans’ hearts and minds. But the direction of the trend is still important context for this ramp-up in authoritarian repression. Apologists for Israel are worried that if everyone is allowed to have their say, they’ll lose their grip on public opinion for good.

When things like this happen, it’s important that we be able to rally support not just from those who agree with our substantive political position but from everyone who cares about free speech as a principle. As Norman Finkelstein told me last fall, when I asked him what lessons the campus protest movement should learn as it goes forward, the best strategy would be to constantly pair our advocacy for Palestine with a defense of our right to advocate for it. He suggested the slogan, “Free Gaza, Free Speech.”

Khalil’s arrest should be a wake-up call for those leftists and progressives who have forgotten why free speech is such a historically important left principle. The Trump administration, with its talk of antisemitism and Jewish students feeling unsafe on campuses, has cynically (but entirely predictably) weaponized precisely the rhetorical moves progressives themselves have often made when watering down free speech in the name of identity politics and concerns about “safety.” If we respond simply by saying that these particular claims about identity and safety are wrong — because the protesters themselves are disproportionately Jewish, or because the justice of the protesters’ cause outweighs the feelings of those Jewish students who do claim to be made to feel “unsafe” — we’ll convince no one who doesn’t already agree with us.

Our mobilizations to free Khalil should be based on a simple rock-solid defense of free speech as such. That commitment has always been central for the serious left, from the “free speech fights” waged at the turn of the twentieth century by the radical labor unionists of the Industrial Workers of the World (IWW) to the Berkeley “free speech movement” of the 1960s. No one who advocates for meaningful social change can trust anyone with the power to enforce censorship rules in the here and now to do it in the way that we’d want, and the whole point of a left-wing critique of our profoundly unequal society is that we want to expand democracy. That ideal is meaningless if the public isn’t free to listen to all viewpoints, even the ones we find the most odious, and make up their own minds.

Free Gaza, Free Speech. And Free Mahmoud Khalil.