OUTSIDE the annual Christmas messages from Queen Elizabeth to the Commonwealth, you will struggle to see a more regal broadcast than the video of Hillary Clinton released today, announcing her conversion to the cause of gay marriage.

The former secretary of state embarks on her screeching u-turn with a moment of self-congratulation, noting her long commitment to gay rights. The idea is to suggest that her views have been changed not by petty considerations such as opinion polls or the pro-marriage declarations of rival politicians. Mrs Clinton reports instead that she was converted by a lifetime of distinguished service and her deep empathy—or as she puts it: "by people I have known and loved, by my experience representing our nation on the world stage, my devotion to law and human rights and the guiding principles of my faith."

Making no mention of her earlier support for federal legislation defining marriage as between a man and a woman, Mrs Clinton instead presents herself in the manner of a national matriarch and living icon of liberalism, happily astonished by an unexpected turn of public opinion. She says:

For those of us who lived through the long years of the civil rights and women’s rights movements, the speed with which more and more people have come to embrace the dignity and equality of LGBT Americans has been breathtaking, and inspiring

The former senator and first lady could have added one more adjective to that last list: mortifying. American opinion on gay marriage has changed with such speed that the swing has left even canny politicians scrambling. A new ABC News/Washington Post poll records a 26% jump in the number of Americans who think gay marriage should be legal since 2004, to 58% now.

In several ways, the manner of Mrs Clinton's announcement looks cautious to the point of cowardice. It is not convincing to argue, as her supporters do, that she is only free to make her views known now that she has stepped down as America's chief diplomat. Her successor at the State Department, John Kerry, has publicly supported gay marriage since 2011, and has not been stoned as a blasphemer on any of his stops around the world to date.

Then there is the fact that she had her husband, ex-president Bill Clinton, prepare the way for her conversion, writing a piece for the Washington Post earlier this month in which he said he regretted signing the Defence of Marriage Act in 1996. There is the detail that she issued her statement in a recorded web video for the Human Rights Campaign, a well-funded lobby group for the gay establishment, thereby shutting down any possibility for pesky questions, as Politico's reporter notes. Finally there is the detail that Mrs Clinton was beaten to her conversion by a lengthening list of conservatives, most recently Senator Rob Portman of Ohio.

But the most damaging aspect of her belated conversion involves something else: where it places Mrs Clinton generationally. The real divide in America on gay marriage is not along party lines (though Republicans are much warier than Democrats). The widest gap involves age. As the new poll notes, a thumping 81% of Americans under 30 back gay marriage. With numbers like that, it is less that the debate has been won among the young, and more that a whole stratum of Americans cannot comprehend what there is even to argue about.

This is at heart a question of visibility. Decades ago, a certain sort of music fan could not see for the life of them why that nice Mr Liberace had never married, let alone imagine that they might know or be related to someone gay. Now, even people in small towns have discovered that some of their sons and daughters are gay. And as Senator Portman explained when he announced his conversion, when he learned that his own, much-loved, son was gay, that changed everything.

In short younger Americans have the eyes to see what was previously hiding in plain sight. Mrs Clinton surely has the same powers of sight, not having spent the past six decades on a farm in Iowa, embroidering Biblical samplers. In coming so late to the wedding party, she thus looks opportunistic and insincere. But worse than that—given that she will be 69 in 2016, were she to run for the Democratic presidential nomination—Mrs Clinton has made herself look older than she really is.