I once helped two prominent bankers write a book on Social Security and, thanks to their connections, we had access to the finest actuaries, to high-performance investment professionals — even to a few clear-eyed academics, and more than a few employees of the Social Security Administration itself.

Up front in that book, we took notice of the “unstoppable, unforgiving glacial forces of demographics that ultimately will destroy Social Security as it now exists.” And after noting that, while in 1950 there had been 16 workers paying into the system for every beneficiary taking payments out of the system, “by 2030 or so, as the last baby boomers approach retirement . . . there will be only two workers paying into the system” for every retiree receiving benefits. We concluded the book with the recommendation that we should transition as soon as possible to a system of participant-owned personal accounts. As we put it in the closing argument: “The choice comes down to this: Stick with the current plan and our already monstrous Social Security debt will continue to grow — so large that at some point the government will be forced to officially repudiate the debt.”

Well, we published that book in 1996 and we have now reached “some point.” The Social Security system today is, in essence, a pay-as-you-go welfare program in which beneficiaries are paid each Monday morning from tax revenues withheld from workers’ paychecks the previous Friday afternoon. Even the trustees of the Social Security system, notorious for understating the urgency of their plight, now say that the “trust fund” will be depleted by 2033. (I deploy the quotation marks to signal to the CPAs among you that I am quite aware that the trustees have no actual trust fund to manage. What they have is a multitrillion-dollar unfunded liability that they will, sometime before 2033, offload onto the rest of us.)

Thirty years ago, when we were writing that book, Social Security was identified ubiquitously as “the third rail of American politics,” which translated politically as “touch it and you die.” A certain governor of Texas, then preparing a presidential campaign, sent word that he liked the book and might make its recommendations part of his platform. His advisers talked him out of it. When he was elected president, he sent word that he might soon take up the subject from the White House podium. His advisers talked him out of it. (He did raise the subject, at least momentarily, during his second term, but he was persuaded to abandon it upon first contact with potential opposition.)

The third rail of American politics has never really been touched — at least not by any serious figure aligned with a major political organization — and so we’ll never really know if the Social Security issue was in fact an instrument of instant political death. What we know is that we now have “a depleted trust fund,” which phrase, you’ll have to admit, falls less harshly upon the ear than does “a repudiated debt.”

We need a new metaphor. We have moved beyond “the third rail.” Given the history of democratic governance, we can predict with confidence that we will not soon see a deliberative process in which the facts are assembled carefully and then assessed soberly by men and women of sagacity and goodwill, after which we will unite behind a disciplined and durable solution to the nation’s retirement crisis. It seems much more likely that a raucous and tendentious scramble will now ensue, producing a last-minute, jerry-built compromise between two of the most powerful of America’s many warring tribes — the political tribe and the financial tribe. It seems more likely, that is to say, that our societal elders will stage a shotgun wedding, hustling an annoyed and anxious bride into holy matrimony (!) with a deeply disappointed bridegroom.

It would have been a long and expensive transition to personal accounts even back in 1996. Today, it will be hellaciously expensive. But it will not be impossible of achievement if we can get ourselves to the right side of those “glacial forces” of demography.

Old people will be intransigent, acutely aware that their diminishing earning power will not be able to cover unexpected income shortfalls. For decades, they have paid into what they were led to believe was their government-protected retirement account. If they are forced to take a real haircut — if they come to believe that they have been scammed by their own government — they could become a hard, high-voting political faction spoiling for a fight. Our focus groups back then, uncontradicted by anecdotal reporting in more recent times, suggest that the single most patriotic cohort within our citizenry — our senior-most citizens — could become hell-bent on regime change.

Young people are different, and in ways that could be critically important for political dealmaking. If you ask young people if they wish to retire at 65 or 75 or 85, they will of course give you the lowest number on offer. But drill down a bit and you will find that their honest answer to the question is . . . whatever. Some dour young people don’t think they will live long enough to become eligible old people. Some yeasty young people think government benefits will be trivial in comparison with their earned income and invested savings. Some young people, wise beyond their years, think the Social Security system is a Ponzi scheme that will never pay off for their generation. Even larger numbers of young people have given no thought whatsoever to the question of retirement income. For these young people, the current system appears to be of genuine importance only to other, much older people.

The trick for tribal elders arranging the shotgun wedding will be to find that fine line between voters who think like young people and voters who think like old people.