The white Christmases that Irving Berlin dreamed of weren't the earliest ones he used to know. He spent his first five Christmases in czarist Russia, and his only recollection of that time, at least the only one he'd acknowledge as an adult, was that of watching his neighbors burn his family's house to the ground in a good old-fashioned, Jew-hating pogrom.

So it's no surprise that when Berlin got around to writing his great Christmas song in 1941, nearly half a century after his family had fled the shtetl of Mohilev for New York's Lower East Side, it was flatly devoid of Christian imagery. It is, for all that, a religious song. It's just that Berlin's religion was America.

"White Christmas" is an achingly nostalgic ballad, evoking a rural America where treetops glisten and sleigh bells ring. This was Currier and Ives country, an idealized winter landscape created for an urban nation that was busily shipping its young men overseas to fight Hitler and Japan. Amid the unprecedented disruptions of the war, "White Christmas," with its implicit assertion that we can somehow get back to this innocent Eden, found a ready audience. Over the subsequent six decades, in a world that's only grown more unstable, Berlin's ode has never lost its power: Roughly 2,000 versions have been recorded since Bing Crosby's initial take.

The success of "White Christmas" paved the way for a whole new genre of Christmas songs. Two years after Berlin's ballad first appeared in Paramount's "Holiday Inn," MGM filmed "Meet Me in St. Louis," which had as its musical centerpiece the bittersweet "Have Yourself a Merry Little Christmas" — a song about loved ones trying to stay together "if the fates allow." (A film ahead of its time, "Meet Me in St. Louis" is about a family resisting corporate relocation.) Two years later came "The Christmas Song" ("Chestnuts roasting on an open fire"), and a year after that, "Let It Snow." By then the American Christmas song was about staying warm in winter, about staying connected to loved ones and traditions. It also practiced separation of church and song.

This was all rather new. Tin Pan Alley hadn't turned out many notable Christmas songs before "White Christmas." It hasn't turned out many since. But for a few years in the middle of the 20th century, it produced a series of songs that remain Christmas standards today.

Many of those Christmas songwriters, of course, were Jewish and the children of immigrants; their deepest drive was to demonstrate beyond all doubt that they were assimilated, cosmopolitan, American. Berlin's father had been a cantor, but Berlin himself, unlike the hero of "The Jazz Singer," wasn't torn between the Jewish piety of liturgical music and the American secularism of ragtime. When he left home at 14 to sing in the saloons of the Bowery, he never looked back. And the religious identity of the composer-lyricist of "White Christmas" and "Easter Parade" was as fuzzy as it was perfunctory. A Jew married to an Irish Catholic, Berlin raised his three daughters as nominal Protestants. Who better to write a non-Christian Christmas song? (Berlin's may have been an extreme case, but in the middle of the 20th century, Jewish assimilationism was so pervasive that it gave rise to the following crack: What's the difference between Reform Jews and Unitarians? Unitarians don't have Christmas trees.)

"White Christmas" was one of a dozen numbers that Berlin wrote for "Holiday Inn," each song commemorating a specific holiday. One hesitates to impute anything so vulgar as a message to a Crosby-Fred Astaire musical, but the message of this musical is that we are all Americans and these are our holidays. Easter belongs to all of us, even if it is about little more than strolling down Fifth Avenue. Christmas belongs to all of us. The religious content of those holidays was fine for Christian believers, but the composer of "God Bless America" preferred to celebrate a common national identity, complete with common holidays that had nonsectarian meanings.

Berlin kept Christmas in the public square and, more than anyone before or since, sent it out over the public air waves. But it was an American, not a Christian, Christmas. And by the crass index of number of recordings sold, and the not-so-crass index of number of spirits touched, Berlin's nonsectarian holiday has been the predominant version of Christmas in this country for the past 60 years.

Now the Fox News demagogues want to impose a more sectarian Christmas on us, supplanting the distinctly American holiday we have celebrated lo these threescore years with a holiday that divides us along religious lines. Bill O'Reilly can blaspheme all he wants, but like millions of my countrymen, I take attacks on Irving Berlin's America personally. If O'Reilly doesn't like it here, why doesn't he go back to where he came from?

Harold Meyerson is editor-at-large of American Prospect and the L.A. Weekly. He wrote this for the Washington Post.