Getting on the freeway the other morning on the way to the office, I noticed the car ahead of me had a Barack Obama ’08 sticker on its bumper. While that’s nothing unusual here in Seattle—it’s practically required—this sticker caught my eye. It was in Hebrew. Guessing that the other car must belong to a neighbor or near-neighbor, I was curious to see the face of the person—actually, my uncharitable thought at the moment called him something else—behind the wheel.

I was in for a surprise. On pulling up parallel with him I realized it was a friendly acquaintance with whom I had enjoyed chatting just the day before. The guy is far from a fool. He is someone who, having traveled a spiritual distance from earlier secular commitments, has been striving to bring his and his family’s life in line with Orthodox Judaism, arguably the world’s most conservative religion.

Experiences like this underline the enigma that Norman Podhoretz, Commentary’s legendary longtime editor, seeks to resolve in his new book. He does so ably, learnedly, charmingly, with his characteristic lucidity and incisiveness—but in a way that falls short, in the end, of solving the mystery. That’s not to say there isn’t a lot to learn and enjoy in this valuable work of scholarly journalism. On the contrary, you’ll find revelations in every chapter.

The question of why most Jews are liberal has a parallel in the question of why many non-Jews have been anti-Semitic. You can narrate the history of Jewish liberalism, as Podhoretz does, or the history of anti-Semitism, and still emerge puzzled.

Those two histories can be seen as a single tangled narrative. There’s a human tendency to form your opinions, including those about politics, in conformity with the social group to which you feel attached through feelings of warmth and acceptance. At some point an association crystallized linking the political Right with the Jews’ traditional persecutor, the Church, and the Left with their liberators, the intellectual movement of the Enlightenment. Even when the Church changed its stance and when the Right emerged more recently as a much sturdier ally of the Jewish people and the Jewish state, the Jews remained locked in a mindset born in the Middle Ages.

Podhoretz starts his story with the origins of Christian efforts to isolate Jews, in ghettos and specially designated geographic areas. In France, Poland, and Russia, as early as the ninth century, Church leaders worried that newly Christianized populations were falling under the sway of “Judaizing” tendencies. After the rule of Ivan the Great, in the late 15th century, it seemed a close thing whether the state religion of Russia would be a Jewish heresy. The “Heresy of the Judaizers” (Zhidovstvuyushchiye) apparently involved such deviations as denying the Trinity and the divine personhood of Jesus. Responding with bloody vehemence, the Orthodox Church prevailed, initiating the technique of the pogrom.

The Enlightenment, hostile to Christianity, seemed the Jews’ ticket to acceptance—except that its spokesmen were often no less hostile to Judaism. Still, the logic of “the enemy of my enemy is my friend” prevailed among the Jews, and the Left because permanently identified with tolerance. Podhoretz rightly finds this mysterious:

“The question thus arises of why the Jews who joined the radical camp were not put off by the egregious anti-Semitism of Marx or that of several other major figures of the socialist movement, including Charles Fourier (to whom the Jews were ‘the leprosy and the ruin of the body politic’) and Pierre-Joseph Proudhon (to whom the Jews were ‘the race which poisons everything [and] the enemy of the human race’).”

Podhoretz quotes Paul Johnson’s observation that Marx’s Capital “became a new kind of Torah.” Through it all, the Jews meanwhile remained oblivious to trends in Christianity that would profoundly alter the attitude of many churches to them. The Judaizing tendency that had earlier stirred in Russia appeared in a different form among English Puritans who circumcised their boys and observed the Sabbath on Saturday. One leader, John Traske, was put in prison from 1618 to 1620 for taking Judaic views to an extreme. Some Pilgrims, on seeking refuge in Amsterdam, went so far as to join the local synagogue.

Their Jewish-themed Christianity fed, of course, one of the roots of American Christianity. Among 19th-century New England intellectuals, some peculiar ideas sprang up as a result. Harvard literary scholars Barrett Wendell and James Russell Lowell independently hit on a theory proposing that the Yankee Puritans had not only an affinity with the Old Testament but actual Jewish family roots. Wendell traced the connection back to Norfolk and Lincolnshire counties, which had once been home to many Jews. When they were formally expelled from the country in 1290, some Jews converted and remained, never totally giving up their Jewishness.

These, so the questionable theory goes, were the ancestors of America’s Puritan settlers. In a further oddity, Lowell and his fellow literary philo-Semite John Jay Chapman later reversed their views and became raging Jew-haters. “Philo-Semitism has often turned into its opposite,” Podhoretz darkly observes.

The American Civil War initiated a period of anti-Semitism, mostly of the patrician variety, that lasted right up to World War II. In the world of electoral politics, meanwhile, the Jewish romance with the Democratic party began with Roosevelt and has been going strong ever since. Since 1928, in election after election, Jews have supported the Democratic presidential candidate, with, on average, 75 percent of their votes.

Podhoretz documents the deepening “reversal of roles between Left and Right on issues of Jewish interest.” When the Democratic party stood for meeting the Nazi threat aggressively while the Republican party tended to isolationism, voting Democratic made sense. But why did Jews favor a presidential candidate like McGovern, an isolationist who threatened Jewish economic interests by endorsing race-based quotas, and had little to recommend him other than—note this well—an ersatz intellectual aura?

Over the same period, on moral issues, the Democrats became the party associated with views anathema to Jewish tradition. Yet the enamored Jews stayed stunningly loyal. Whether on gay marriage, suicide, or euthanasia, Jews became the most liberal of all liberal demographic opinion groups.

What accounts for it all? Podhoretz goes back to Johnson’s observation about Capital as the new Torah of the Jews. Much as in religion, where most Jewish families downgraded their faith from the Orthodoxy of ancient tradition to various modern compromise positions, so, too, having become born again in the socialist church, the Jews nevertheless progressively loosened their orthodoxy there too. Liberalism is to Marxism what, among Jewish denominations, Reform is to Orthodox.

The problem with the parallel is that there are few if any fervent Reform Jews. Liberal Jewish religion is by its nature blasé. But there are many fervent Jewish liberals, and that is precisely the enigmatic fact we are trying to shed light on. In seeking to do so, an analyst is drawn to settling on one special reason for Jewish liberalism, above all the other possible reasons. Yet it may be that this particular condition can only be explained by reference to several different causes. Here are a couple to consider.

Podhoretz too quickly dismisses the most popular explanation, favored by Jewish liberals themselves, that there is an essential Jewish quality—compassion—to which liberalism, or least liberal rhetoric, speaks in a way conservatism doesn’t. This isn’t necessarily to say Jews are more compassionate, but rather that we think of ourselves that way. The Talmud goes so far as to say if you meet someone claiming to be a Jew who shows no mercy to the needy, you should consider his lineage suspect: “Be certain he is not a descendant of our forefather Abraham” (Beitzah 32b). Maimonides codifies the observation as a matter of Jewish law.

But the contributing factor that Podhoretz leaves out entirely, and I find this surprising from the author of a book with the title Making It, is the social prestige conferred by one political stance as compared to the other. “One of the longest journeys in the world is the journey from Brooklyn to Manhattan—or at least from certain neighborhoods in Brooklyn to certain parts of Manhattan,” goes the memorable and very Jewish opening sentence in Podhoretz’s memoir.

You would have a hard time finding a people more finely attuned to degrees of prestige. Once, religious scholarship was the highest merit among us. Now, it’s a certain melding of academic and material accomplishment that really impresses. And boy, does it impress.

On just these terms, there can be no question that of the two poles in American politics, one is a prestige accoutrement. Call it the McGovern Factor. In the circles in which Jews overwhelmingly travel, liberalism is a sign of having made it intellectually and socially, where conservatism smells of everything backward and retrograde. I speak of perception, of course, not reality.

An Obama bumper sticker, whether in Hebrew or in English, says “I’m smart. I’m enlightened.” A McCain-Palin bumper sticker, like the one I’ve still got on my car, says, “I’m not.” For many Jews, I regret having to report, that makes all the difference.