This Thanksgiving, millions of families—Jewish, not Jewish, a mix of the two—will gather around tables to give thanks for a country that has historically been, for us as a people, a refuge, and an inspiration. It is also now, for many, a place whose virtues are shadowed, where bizarre and repulsive threats seem to have suddenly burst forth out of nowhere. We’re all going to be talking about it, so we might as well be prepared.***Over the past year, Jews have been harassed online with horrifying energy—regularly called “oven dodgers,” our faces Photoshopped onto dead bodies from gruesome Holocaust pictures, gleefully warned to prepare for our next coming genocide. (The eeriest tweet I received was a simple clip from a WWII movie of an Aryan-looking woman watching her Jewish neighbors being rounded up, and screaming in ecstasy: “Goodbye, Jews!”) The vile messages seemingly became more threatening with the White House appointment of Steve Bannon, who boasted last summer about having turned Breitbart News into “the platform for the alt-right”—the fancier name that Twitter and Facebook would like us to use for the people we used to call “thugs” or “Nazis.”But while I wish I could say that mainstreaming of anti-Semitism in America is solely a product of Donald Trump’s campaign for the presidency, the truth is much scarier. The blatantly racist and anti-Semitic alt-right movement that emerged during Trump’s campaign in fact mirrored the insinuating anti-Semitism that had already captured a prominent sector of the progressive left during the Obama years. This trend was apparently clear enough to the operatives who ran Hillary Clinton’s campaign that they decided that allowing the candidate to be seen in public talking to Jews on issues that concern them during either the primary or the general election campaign was a clear negative, to be avoided at all costs—a decision that likely lost her the state of Florida, and perhaps even the presidency.The threat to our community is a new one, because it is coming from both extremes of the political spectrum and infiltrating mainstream discourse among both Republicans and Democrats. Together, anti-Semites of the right and the left are spreading a political virus once contained at the fringes of our society into a broad beat pulsing beneath the entire American political conversation. To understand why this is so dangerous, it is necessary for partisans on both sides to admit that it’s not just the other side that has a problem; we all do.To do so, we must first be clear about what anti-Semitism is—and is not. Anti-Semitism is not a social prejudice against Jews; it’s a conspiracy theory. In fact, it’s the oldest and most powerful conspiracy theory in the West. You can be an anti-Semite without being particularly prejudiced against Jews in your personal interactions with them, and you can hold prejudiced views about Jews without being an anti-Semite. The person who finds Jews to be loud and vulgar and doesn’t want them in his country club is a bigot; if you asked him whether the reason he doesn’t like Jews is because they nefariously control the government and all the banks and are bent on world domination, he’d probably look at you as if you were insane.Conversely, there are people—including some Jews!—who happily watch Seinfeld and eat bagels and lox, but who also believe that a secret conspiracy of Likudniks dragged America into war in Iraq, or are responsible for the latest financial crisis, or border crisis, which these Jews present in manipulative ways in the media, which is secretly controlled by George Soros or Sheldon Adelson. To any normal person, whatever their prejudices, the core of anti-Semitic thinking is sheer insanity. To anti-Semites, it is revelatory—whatever their political affiliations.Let me show you.In a video widely shared on the eve of the election, a young Trump supporter was filmed outside a rally explaining that “we need to make this country great again, to end a lot of things including … Zionism, which is huge, and it’s probably the biggest problem that we have in this country today, and around the globe—which is, a few people controlling pretty much everything. …” Now read the words of Joy Karega—the leftist professor at Oberlin fired (curiously right after Trump’s election) for asserting that ISIS is an arm of Israeli and U.S. intelligence agencies and that Israel was behind 9/11 and the Charlie Hebdo massacre in Paris. Evidence that “Israel” was simply code for “the Jews” was not hard to find in her postings, either. She posted a picture to Facebook of the Jewish banking heir Jacob Rothschild with the words: “We own your news, the media, your oil and your government.”While anti-Jewish prejudice—like all forms of prejudice—is ugly, does damage to the fabric of our pluralistic society, and if acted upon is illegal, it doesn’t today represent a threat to the republic. Anti-Semitism does.For more than a decade now, it hasn’t been hard, for Jews at least, to hear versions of the same insanity echoing on both sides of the political aisle. Post-9/11, right-wing paleo-cons like Pat Buchanan found renewed life for their anti-Jewish fixations, which were often the same as those spread by left-wing activists like those in Code Pink and countercultural icons like Amiri Baraka, who retailed vicious theories about how the Mossad toppled the Twin Towers after warning Jews against showing up at work that day. Popular political candidates talked conspicuously about “Paul Wolfowitz and Richard Perle” leading America to war in Iraq, as though either was named George Bush, Dick Cheney, Donald Rumsfeld, Colin Powell, or Condoleezza Rice. And whatever one thinks about the final merits of the Iran deal, it is hard to imagine any fair way to characterize that debate’s relentless impugning of the “war-mongering” motives of “rich donors” and “foreign lobbyists” last summer without drawing similarities to the Trump campaign’s dog whistles to anti-Semites.Conspiracy theories about powerful Jewish cabals that use their money and control over the media to control the U.S. government and torque foreign policy contrary to U.S. interests are pure anti-Semitism, whether they are being spread by Stephen Walt or Steve Bannon. The idea that Jews—alone among peoples, and despite their lavishly-documented 3,500-year history—should not have their own state, in a world of nation-states, or that the Jewish state is uniquely responsible for a host of things well beyond its own borders, is anti-Semitism. (Criticizing how that state is run is not.)The confluence of alt-right and progressive left anti-Semitism in America reached its most absurd apex in the days before this year’s election, when Trump’s campaign released an advertisement—one created by his own representatives, not something that could be dismissed as nuttiness on the part of fringe supporters—that trafficked in blatantly anti-Semitic imagery and references, singling out images of Soros, Janet Yellen, and Lloyd Blankfein as “global special interests” who “control the levers of power.” In response, leftist activists and journalists actually came out in defense of the ad, including one who openly asserted to a Jewish interlocutor that it wasn’t, in fact, anti-Semitic: “Arguing that people who are powerful get a pass because of their religion seems like a bad way to take it.”The election itself has apparently made people even more confused. “Sympathy gap is telling,” tweeted the writer Ta-Nehisi Coates. “Worth contrasting the ‘complexity’ offered Trump’s supporters with, say, those who supported Louis Farrakhan.” Leaving aside the fact that Farrakhan is himself a Trump supporter—and thus a perfect example of the alt-right and radical left coming together in a grotesque Ouroboros—the metaphor was a strange one. In fact, over the past few years, Farrakhan has been quite openly re-embraced by mainstream outlets and figures, appearing in Ebony’s 2015 Men’s Issue and pictured on Instagram with prominent hip hop artists, radio personalities, reality-TV stars, major pop culture celebrities, and—this last one is so tragically absurd as to almost be funny—even Russell Simmons, the chairman of an organization allegedly “dedicated to fighting intolerance and promoting understanding between ethnic or religious communities.” So maybe it shouldn’t have been surprising when Kanye West announced, two years ago and to little or no pushback, that he was making a hagiographic documentary about Farrakhan—“it’s important that while he’s still alive he sees the people appreciate his message,” West said, about the man who to this day revels in talking about “the Satanic Jews that control everything and mostly everybody.” For West to inspire genuine wrath on the part of both the commentariat and his fans, he had to say he supported Donald Trump.Many of the left’s most toxic voices do not, at least as of right now, occupy positions of influence within the mainstream of the Democratic Party—indeed, most are openly hostile to it. But if you’re a Jewish Democrat, it’s worth noting that the Breitbartians also existed outside the establishment Republican Party, until … they didn’t anymore. And the reason it happened so fast is because conspiracy theories act like gasoline, especially in societies whose civic institutions have dried into tinder.The dark truth is that neither Jewish Democrats nor Jewish Republicans can afford any longer to take the support of their own party for granted. If you think this suggestion is exaggerated, at least when it comes to your political party, in which you have always felt at home, ask yourself whether you’ve heard people of power and influence on your side encourage the propagation of any of the following: 9/11 trutherism, undue Israeli influence on the U.S. government, the menace of an octopus-like globalist conspiracy. Have prominent members of your party then vouched for these people, and told you that their troubling words can be safely ignored?Ask, and ask again. Because it doesn’t take much grounding in recent history to imagine what happens to political movements and even entire societies that substitute conspiracy theories for rational thought: They decay.* * *I understand why many acculturated people believe that the new hatred of Jews is nothing more than a silly pastime of a handful of ultimately powerless morons. The problem is that this is yet another example of the bubbles of self-satisfaction and ignorance we have all been forming—shaped by lives that are increasingly circumscribed not only by demographics but also now by Facebook and Twitter.Physical dangers to Jews in America are quite real, as anyone who regularly passes by security guards in order to attend synagogue or drop off their children at a Jewish school already knows. While Jews constitute 2.2 percent of the U.S. population, according to an FBI report released earlier this month, we are the victims of 52.1 percent of the religiously motivated hate crimes in America (Muslims are the second most-victimized group, at 21.9 percent). Yet while many of us are deeply—and rightly—concerned with violence directed against blacks, Muslims, Hispanics, gays, women, and other groups, especially in the age of Trump, the one group that is consistently and conspicuously missing from the victim lists that circulate on campuses and elsewhere is Jews.The absence of Jews from the lists of those whose vulnerability merits attention is a measure of how far the disease of anti-Semitism has spread in sectors of society that otherwise pride themselves on their compassion for minority groups. But it is also a product of our own confusion of anti-Jewish prejudice and anti-Semitism. We have treated the revival of a corrupted conspiracy theory as a small burst of simple social intolerance—the answer to which, of course, would be for us to allay the fears of those around us by downplaying our difference, highlighting our positive contributions to society and concern for others, and making sure we continued to say the right things at cocktail parties. “I think nervous Jews should mostly work on conventional, non-Jewish-specific issues,” writes Jonathan Chait, in an article that perfectly captures this century-old conventional American Jewish wisdom about the personal and political benefits of “passing.”This is precisely the wrong approach.Why is this happening now? And why, of all places, here in America? The answers are, no doubt, complex—rapid change, new technologies, a scary economic climate in which there are many more losers than winners, and other such causes, which are very real but have also been true in other times and places. But there is also something unique about the relationship between American Jews and America that I fear has become frayed—and I fear that fraying is the cause of our current problems, and also America’s.From the very beginning, there was a tacit agreement made between this country and its Jews: You, America, give us liberty and freedom from the extreme degradation and oppression we experienced everywhere else and, in turn, we Jews, will gift you with our … Jewishness. With Jewish thinking, and Jewish reflexes. With the ideas and impulses, honed over thousands of years, that could help a country create an unmatched economy, unparalleled creative industries and artistic and literary cultures, social and civic organizations, and more.America, at least so far, has kept its side of the bargain. But we have not.To be clear, this is obviously not to say that Jews cause anti-Semitism—only bigots say that—but rather that we possessed the means to help non-Jews combat its rise but largely abandoned them. We did not safeguard particularly Jewish thinking, and we did not—for some completely understandable reasons—demand that our fellow Jews stand guard over their inheritance and their communities, and strengthen their Jewish sense of self. Instead, many of us ran—into secularism, into America—having come to believe that no matter what we knew or did, we would always, essentially, be Jewish. We believed that because Hitler told us so.Three generations later, what’s amazing is not that the children and grandchildren of these people assert broad disconnection to some random pollster. It’s that so many are still hanging on by whatever threads they can find.But now, so is America. We are living through the negative side of the American Jewish paradox: The less Jewish we are, the less American our country becomes.Here’s the truth that our communal leaders have been nervously dancing around for far too long: You are free to assimilate; you always have been. But you can’t abrogate both Jewish knowledge and Jewish experience and still be meaningfully Jewish. By diluting your Jewishness, you are depriving America of the gifts your ancestors brought here, and in doing so you are damaging a country that has been good to us.Being face to face with Jews, and having to acknowledge our difference, and decide whether we were worth accepting, was good for Jews—and good for America. Tolerance, in exchange for pretending to be someone else, is a far lower ask; it’s a bargain that frightened people make, and it creates an emptiness where monsters breed. Had more of us actually looked and acted like Jews—or even just talked to more people who do—we might not have been caught unaware.Jews who asserted the particularity of their nationalism, their religion, their ethnicity, made America a better place to live for everyone. This Thanksgiving, America needs its Jews to be Jewish again—now more than ever.***Like this article? Sign up for our Daily Digest to get Tablet Magazine’s new content in your inbox each morning.