California Gov. Arnold Schwarzenegger kisses his wife, Maria Shriver, after taking his oath of office in Sacramento in January 2007. The couple announced their separation Monday. (Marcio Jose Sanchez/AP)

Sure, it happens. But we don’t talk about it.

Paw through the increasingly numerous pages of the New York Times wedding announcements on the way to June, and you will spot nary a sign of the time-honored Marriage For Position, or Marriage For Wealth, or Marriage for, well, anything really, save the sheer and utter delight of requited and potentially eternal love. Not that I have anything against the sheer and utter delight of requited and potentially eternal love. Please grab me some if anyone brings it around on a tray.

But we should remember that marriage wasn’t always like this.

One of the reasons the institution has endured so long is its ability to provide a relatively stable framework for two unrelated individuals attempting to make a go of it. Within its parameters, you could create a system of loyalties where none had existed before. So it was a handy tool for kingmakers to keep on the proverbial belt. There was a reason Philip I of Spain sought Mary I of England, and it wasn’t the lovingly baked meat pies she insisted on shipping to him overseas, or why Europe waited with bated breath for the Austrian Marie Antoinette to come of age and be shuttled off to France. There’s an innate power to the linkage itself, magnified tenfold when it brings a Membership of some kind.

There’s a certain naive appeal to the idea that young Arnold Schwarzenegger would arrive in America and instantly seek to ally himself with Maria Shriver, scion of the Kennedy Political Dynasty. But life is never quite so simple, nor quite so cynical, and I can’t prod into their marriage any more than the glass walls of political and celebrity life have already rendered it visible. What matters is not how it began but what it became: a source of strength for both parties for reasons both historical and modern. For even if it were partially a dynastic marriage of the old sort, it was a radical departure from what that term once meant, with Cabots and Lowells nodding at each other from their sides of the aisle and murmuring vague disapproval over the consomme. A Republican bodybuilder? A Kennedy? No one in his right conventional mind believed it would last.

But last it did, producing children and a governorship, despite some publicized wrinkles. And when Arnold came under fire with accusations of inappropriate behavior, Maria’s support proved crucial, with her response that the allegations “show why really good people don’t want to go into politics anymore.” Like most political partnerships that draw attention in the public eye, the linkage became part of their individual charm. First Dude Todd and Sarah. Bill and Hillary. Ahnuld and Maria.

But political marriages are like printers. I expect them to work, but I’m not surprised when they don’t. There’s an obvious parallel between weddings and politics: Everyone wants to get married, fewer want to be married; everyone wants to win an election, fewer want to govern.

These days, dynastic marriages are out of favor.

Perhaps we find them jarring. The popular notion of marriage is heavy on gowns and flowers and hearts beating as one and light on the nitty-gritty reality of actual partnership, the stubborn engine that powers most famed political unions, from Eleanor and Franklin on down. We like to pretend, when we imagine marriage, that it only happens to people Ideally Suited For Each Other Brimming With Ultimate Love. Look at Prince William — the sort of individual for whom this type of league used to be reserved, wedding his college girlfriend in aw-shucks apolitical style. That may be the essence of weddings. But marriages are something else. So these traditional alliances crop up in politics instead. Not, often, in the traditional sense of linking dynasties, but offering a new kind of ammunition, a strong bond not to the established power of a family but to the dynamic power of an individual.

Maria and Arnold may well pull through this patch, or they may go their separate ways. Perhaps no marriage can survive in the hothouse of celebrity. But the fact that theirs did for so long actually makes me hopeful about the power of the institution.

At a commencement speech at the University of Southern California in May 2009, Schwarzenegger said the three secrets to success were “number one, come to America. Number two, work your butt off. And number three, marry a Kennedy.” “Kennedy” was a key word there. But “marry” was, too.