The Brooklyn Commons, according to its Facebook page, “is a community & educational center dedicated to healthy communities, individuals, [and] environment.” It provides office space and venue support to a number of progressive organizations, including Jacobin magazine and the Right to the City Alliance. And today, by virtue of who it is hosting, the neighborhood hangout is also dedicated to exposing 9/11 as a “deception imposed on our nation by the Israeli/Zionist and Neo-Conservative cabal that controls our government and media.”The speaker the Commons is hosting to promote this bit of slander is one Christopher Bollyn, a prominent anti-Semitic conspiracy theorist whose website finds a Jewish connection behind everything from 9/11 to the Kennedy assassination. This event was spotted by Daniel Sieradski, founder of the progressive Jewish website Jewschool.com, who has been organizing other members of the progressive community to condemn Bollyn and urge the Commons to cancel his event. But the Commons has spurned these calls—possibly because, as Sieradski uncovered, the proprietor is herself a 9/11 truther.This is of course distressing. But much as we might like to, it is probably impossible to eliminate every instance of anti-Semitism—or racism, or sexism, or Islamophobia—from our communities. Often, what matters more is not the incident itself but how the community responds to it and what we learn from it. And Bollyn’s invitation to speak at a progressive institution like the Brooklyn Commons carries with it several lessons for progressives (and non-progressives) concerned with the fight against anti-Semitism.1. It is wrong to say progressive organizations will never condemn anti-Semitism among their own. There is substantial concern that progressive organizations are increasingly turning a blind eye to anti-Semitism, at least when given the barest cloak of anti-Zionism. It is a concern I share, and Siederaski raises it as well, dubbing the Bollyn invitation evidence of “the ongoing failure of the Left to recognize and acknowledge the seriousness of antisemitism within its own ranks.” So it is important to note at the outset the impressive range of progressive organizations and commentators who did raise their voice against the Bollyn and the Commons for hosting him. Nine of the Commons’ resident organizations have condemned their own space for hosting Bollyn’s “antisemitic politics,” and all of Bollyn’s other upcoming venues—including the Hartford Unitarian Society and the venerable D.C. institution Busboys and Poets—have cancelled his appearances.One could fairly rejoin that we should not fall over ourselves to congratulate anyone for condemning such an open and obvious anti-Semitic case as Bollyn. But given the rise of the alt-right’s naked anti-Semitism on the right end of today’s political discourse, we can no longer take even the obvious cases for granted. If it seems Jews like myself pay more attention to left-wing failures on the anti-Semitism front, it is not because the left is “worse” on the issue than the right. It is because the left is my community, and I expect it to know better. Here, many organizations have at least taken the first step, and that is worth praising. But there remains significant work to be done, and the real question is whether progressive groups will be willing to go beyond the easy work of issuing a condemnation.2. There is a space for anti-Semitism on the left. Perhaps the favorite mantra of the Commons’ critics is that “there is no space for anti-Semitism in the progressive community.” This self-soothing declaration founders upon the simple fact that, apparently, there is such space. Rather than denying what is manifestly true, it is worth reflecting on how such space came to exist. Regardless of the ultimate result, there is a reason why someone like Bollyn books events at venues like Brooklyn Commons and Busboys and Poets while, say, Dinesh D’Souza does not. He does so because he believes he can find an agreeable audience in such spaces; that the environment there is receptive to his noxious ideology. That alone is suggestive of a serious problem. Yet, when progressives wonder how a 9/11 truther who is (at least) tolerant of naked anti-Semitism rose to become leader of an important progressive space, part of the answer must be “because our community was not structured to prevent it.”Much as conservatives who insisted against all the evidence that there was “no space for racism” in their movement have been forced to act as if the Trump nomination was a wholly unpredictable deus ex machina, progressives will never be able to effectively combat events like Bollyn’s until they reckon with the elements and attributes of their communities which are seen by anti-Semites as fertile soil. Instead of taking comfort in viewing Bollyn’s attraction to our community as an impenetrable mystery, we must look without flinching into how the basic structure of our communities produces this toxic fruit.For example, even among Bollyn’s opponents, many rushed to assure their readers that they continued to believe that many if not most claims of anti-Semitism are made in bad faith and so can be ignored. Such a view functions against Jews the same as it does when conservatives deploy it against people of color calling out racism: as a means of denying prejudice and bigotry in our own ranks, of dismissing those claims we’d rather not reckon with, and of recasting the claimants as unreliable at best, liars at worst, and justly ignored either way. Such an outlook is unlikely to result in anti-Semitism being taken seriously beyond the most obvious cases. Indeed, such a view is incompatible with truly viewing Jews as equals.3. We need to stop restricting our conception of anti-Semitism to the far-right and white supremacist affiliations. Many of the efforts to organize against Bollyn have relied heavily on his associations with a bevy of right-wing and neo-Nazi groups, such as the American Free Press and David Duke. This is understandable—it provides an easy shorthand demonstrating to sometimes-skeptical leftists that Bollyn is the real anti-Semitic deal. Yet it is also apparent that over-reliance on these connections is a sort of crutch—we use it because we are afraid that, without this link, even the most obvious anti-Semitism will not be recognized. I’ve termed this phenomenon “Innocent until proven Nazi.” When objecting to anti-Semitic content posted by Vassar College’s Students for Justice in Palestine chapter, the smoking gun was that its column came from a White supremacist publication and that its cartoon was originally published by Nazis in 1944. When Jewish Voice for Peace disassociated itself from “anti-Zionist” activist Alison Weir, it did not cite her belief that the medieval blood libel was really accurate or her description of Judaism as a “supremacist faith”; indeed, it could not bring itself to condemn anything she said about Jews at all. Their objection was rather who Weir was speaking to—white supremacists, neo-Nazis, and Holocaust deniers.Yes, it is true that Bollyn has long and deep associations with the American far-right. But put simply, we should not need to demonstrate such bona fides to convince anyone that “the Israeli/Zionist and Neo-Conservative cabal that controls our government and media” is an anti-Semitic canard.The “Innocent until Proven Nazi” paradigm illustrates at least three distinct problems in how the left responds to anti-Semitism. First, of course, it indicates that anti-Semitism will not be recognized unless it takes the form and gravity of a Klansman’s robe—leaving us dumbstruck in the wide range of cases where the wrong is less overt or simply has a different genealogy. Second, it shows the extremity of the default disbelief of anti-Semitism claims—unless one can literally show a Nazi connection, the assumption is that large swaths of the left will presume the charge is bogus. And third, it implies that there is no such thing as homegrown left-wing anti-Semitism—if there is a problem, it is a problem of conservatism somehow managing to infect our ranks. This allows us to avoid the difficult work of seeing how we—not through reflection or infection, but of our own accord—are implicated in the problem.4. Just because you oppose other forms of racism doesn’t mean you recognize or oppose anti-Semitism. Before it was revealed that the Commons’ proprietor was herself a 9/11 truther, the most bizarre communique out of the organization came from its social media director, who claimed that “nothing anti-Semitic jumped out at me” from Bollyn’s website (a website replete with references to the Protocols of the Elders of Zion and “Zionist Jewish” plots of global domination). How could an employee of a progressive space not recognize the obvious anti-Semitism before her eyes? The assumption is that, simply by virtue of one’s progressivism, one must automatically not just oppose anti-Semitism, but be well-attuned to identifying it and effective at combating it.Many progressive groups, in articulating their opposition to anti-Semitism, frame their position in precisely those terms: the natural extension of their parallel commitments to opposing racism or other forms of oppression. As a statement of solidarity, such a stance is perfectly adequate. But as a description of anti-oppression work, it leaves much to be desired; it assumes that their commitment to opposing oppression generally gives them an adequate toolkit to identify and confront anti-Semitism specifically. Opposition to anti-Semitism is not a BoGo deal; it does not come free with one’s anti-racist work. One does not oppose anti-Semitism simply because one opposes racism. It requires independent analysis and effort, and a willingness to acknowledge the gaps and partiality in one’s own perspective. One does not, as Kimberlé Williams Crenshaw put it with respect to racism, transcend anti-Semitism “by proclamation alone.” Without a deep understanding of Jewish history and experience, and a robust sense of how anti-Semitism operates as a specific vector of oppression, one is unlikely to have solid instincts regarding what is anti-Semitism and how to oppose it. Groups truly committed to undermining anti-Semitism cannot assume that they’re already “there” on the issue. It is entirely possible to vigorously oppose racism and yet be deeply implicated in anti-Semitic domination—particularly if one has invested considerable resources into elucidating the former while largely neglecting the latter.5. It’s one thing to challenge anti-Semitism in the easy cases. It’s quite another when it’s hard. The first point above was that many progressives, to their credit, have condemned Bollyn and the Brooklyn Commons. The last lesson is that this is not enough—it is Dietrich Bonhoeffer’s “cheap grace.” Anyone can issue a statement condemning a white supremacist-affiliated 9/11 truther. It is cheap, it costs nothing. Costly grace is “the treasure hidden in the field; for the sake of it a man will gladly go and sell all that he has.” One cannot only oppose anti-Semitism when it is cheap to do so; the real test is what one does when opposition comes with a cost.Will the resident organizations of the Brooklyn Commons abandon the space? That would come with a cost—the community clearly is one that matters to them, and New York real estate is expensive. Will the progressive organizations which condemn Bollyn be open to other criticisms which strike closer to home, which indict their own practices? That would come with a cost—it may force reassessment of cherished beliefs, or disturb significant alliances. Will they commit to grappling with all allegations of anti-Semitism, not just those that come in the obvious garb of a neo-Nazi? That would come with a cost—it would mean abandoning the easy narrative, still clung to by many, that many if not most anti-Semitism claims are leveled in bad faith or are the product of Jewish hysteria. Will progressives demand that we all take the very radical step of believing Jews, taking seriously what we say about ourselves, even when it diverges from what others are saying about us? That would come with a cost—it cedes Gentile control of conversations, it denies them the epistemic privilege they’ve come to enjoy, and it precludes the reliance on a few “good Jews” to evade reckoning with the testimony of the rest.The condemnations are a start, and not an unimportant one. But they pale in comparison to what is required next. Fighting anti-Semitism in our movement means abandoning the delusion that it is not our problem, abandoning the crutch that it is a simply a right-wing infection, abandoning the belief that we already know what we need to know, and, finally, abandoning the notion that one can truly oppose anti-Semitism without ever giving up anything dear to us.