Around The Daily Beast office, I’m known for my spot-on Bernie Sanders impersonation. To my colleagues, it seems studied, but to me, it’s just familiar. I’ve known Bernies all my life.

The same is true for Bernie’s atheism. A recent profile in the The Washington Post, headlined “Why Bernie Sanders doesn’t participate in organized religion,” depicted the senator as possessing a quixotic blend of cultural Judaism, kinda-sorta belief in God, and political idealism.

To many Jews, however, this mix is hardly unusual. It’s familiar as chicken soup and matzo: the basically secular, basically atheist Jewish Democratic Socialist, part of the erstwhile 20th-century American Jewish Left populated by the likes of Irving Howe, Woody Guthrie (not Jewish, but married Jewish, raised kids Jewish, sang Jewish songs), Irving Howe, Alfred Kazin, Hannah Arendt, and, later, Gloria Steinem, Bella Abzug, and Yippies like Jerry Rubin and Abbie Hoffman.

The Jewish Left included Socialists, Communists, labor unionists, Zionists, and even future neo-conservatives Saul Bellow, Sidney Hook, Norman Podhoretz and Irving Kristol, who began their biological and political lives in the same social milieu as Bernie Sanders before they turned to the right in the 1960s-’70s. (Their story has been told many times, most recently in Daniel Oppenheimer’s new book Exit Right).

Although culturally Jewish, religiously-nonbelieving Socialism may seem like a quirky blend today, it’s part of Jewish history, complete with red-diaper babies, Socialist Jewish summer camps, and bitter persecution during the McCarthy era before reemerging in the New Left of the 1960s.

Even the Forward, the Jewish newspaper where I also write a column, began its life as a Yiddish Socialist daily, Forverts, edited by Abraham Cahan. (Like everyone on the Left, it was attacked by redder Socialists for being not Left enough.) For many recent Jewish immigrants from Eastern Europe, progressive politics was the new religion, and the only real question was which sect—liberalism, socialism, communism—one liked best.

As the Yiddish joke goes, these Jews knew three worlds: the alte velt, the Old World of Europe; the neue velt, the New World; and Roosevelt.

What kind of Judaism is this? Certainly, as the Post said of Sanders, it is a cultural affiliation. It’s not a coincidence that Larry David does an even better Sanders impression than I do; they’re culturally the same person. In an earlier decade, I suspect Sid Caesar, Mel Brooks, George Burns (a distant cousin of mine!), and even Henny Youngman might have acquitted themselves equally well.

But secular, progressive Judaism is, itself, a kind of religion. While dispensing with the God of the alte velt—if the Enlightenment didn’t kill him, the Holocaust certainly did—leftist Jews of the 20th century maintained a prophetic, religious zeal for justice.

Some of this came from within the Jewish tradition, both as a matter of Biblical injunction (“Do not oppress a stranger, for you know the heart of a stranger as you were slaves in Egypt,” a commandment today’s Jewish Trump-supporters might ponder) and of national character. European Jews were oppressed for thousands of years: burned, exiled, forbidden from owning property, banned by polite society. And even when, in the 18th and 19th centuries, “civilized” Jews from France and Germany were granted the benefits of citizenship, the “backward” Jews from Eastern Europe were still subjected to pogroms.

When the descendants of these Jews came to the United States, the intellectuals among them brought their history of marginalization and their firm belief that progressive change—whether revolutionary or gradual—was absolutely necessary as a matter of simple morality. America was the goldene medina, the Golden Country, where finally everyone could be equal, regardless of birth or race. Yet there was obviously a gap between that ideal and reality, and into that breach rushed a generation of Jewish progressives. Some championed the New Deal, others joined the New Left, some were hunted down as communists and provocateurs. But all participated in a Jewish version of “civil religion”: a basically secular moral order that agitated for progressive social change.

Sanders’s political idealism is obviously cut from this cloth. Part of his appeal to progressives is that he calls Wall Street “immoral and wrong,” countering the religious rhetoric of conservatives not with namby-pamby liberalism but with a moral, prophetic call, however unrealistic it may be. “I think it is important that a sense of morality be part of our politics,” Sanders told the Post. And one gets the sense that he believes it.

Now, is this really “religion”?

It depends what you mean. By Christian standards, not quite. Sanders did his best when asked, point-blank, if he believes in God. “I think everyone believes in God in their own ways,” he said. “To me, it means that all of us are connected, all of life is connected, and that we are all tied together.”

Well, that’s great, but in that case, Richard Dawkins and Sam Harris believe in God. If this is theism, then what is atheism?

No, Bernie was being political. He knows that atheists are widely despised in America—it’s one of the few permissible prejudices—and that many of them are arrogant, obnoxious jerks. He also knows that his own quasi-atheism is yet another reason he is unelectable in a country that still identifies as over 80% religious. (Still another reason may be the kibbutz at which he volunteered, but now refuses to name—perhaps it was more Communist than Socialist.)

So he’s couched his secularism in a religious-seeming garb. Generously, we could call this “skillful communication.” But it’s not religion as that term is usually understood in Christian contexts.

On the other hand, Judaism has long had a different understanding. The old saw that “Judaism is a religion of deed, not creed” is, of course, a simplification. But it’s more true than false. To be a good Jew, in Orthodox religious terms, is to obey the ritual and ethical commandments. A handful of those require belief, but the vast majority do not. In college, I remember a teacher of mine, an Orthodox rabbi, telling me that “To be a good Jew, you need to believe in one God, or fewer.”

Likewise among non-Orthodox religious Jews, for whom religion is more about practice than faith, more about action than intention. Even if belief retains some role, it often sits on the epistemological back burner. It’s there, but it’s not a big deal.

Nor—especially for Reform Jews but certainly for secular ones—is the Bible and its legal norms. Secular Jewish morality, and most of Reform Jewish morality, is based on conscience, reason, compassion, and reflection, not Scripture. The Bible may be edifying, but ethical reasoning is primary.

To repeat, this is not true of everyone. Some Hasidic Jews are almost evangelical in their emphasis on personal relationships to God. Many Renewal and Reconstructionist Jews have non-traditional theologies—a bit like Sanders’s—but still emphasize the importance of spiritual experience, ecstasy, or contemplation.

But if we are asking whether Sanders is “religious” in Jewish terms, the reply must be that he is. The question isn’t whether he went to a Passover Seder or stood outside the doors on Rosh Hashanah, and it certainly isn’t whether he believes in a creator deity. Sanders is secular, he is atheist or close to it, and he defines morality in ethical, not ritual or traditional or authority-based, terms.

But if Sanders wants to call that religious, he’s got a long progressive-Jewish lineage to back him up. When he says he “believes in God in [his] own ways,” he’s not speaking as a quirky, uncombed Socialist from Vermont. However unelectable it may make him, he’s speaking as part of a century-plus tradition of progressive secular Jews who changed the face of America.