For as long as students of political cliche can remember, the U.S. Social Security system has been called the “third rail of American politics.” Like the steel beam that brings current to subway trains, if you touch it, you die – or at least end up with blackened fingers and a ridiculous perm.

We now know the cliche is false, thanks to President Bush.

“I’ve touched the third rail,” the president has said often, and with an air of self-congratulation, since proposing to reform Social Security with individual investment accounts.

And sure enough, when the president boldly stretched out his hand and dared to seize the issue, political observers covered their eyes and ears in horror and – nothing happened.

And I do mean nothing. Not only has the president not suffered any political damage from his reform attempt, but the very possibility of reform seems as remote as it ever did.

Obviously we need a new metaphor. How about, “the brick wall of American politics – run up against it and you’ll get nowhere”?

It’s not as pithy as “third rail,” I know. But what it lacks in pith it makes up in accuracy.

The speed with which Mr. Bush’s Social Security plan was declared “in danger” and then “mortally wounded” is surprising even by the standards of Washington politics, where the short attention span of the practitioners guarantees an ever-changing series of urgent issues and crises-of-the-century.

There are good reasons for the difficulty Mr. Bush has encountered. He has failed with his three most crucial constituencies: the public, his Democratic opponents, and his Republican allies.

Indeed, the more Mr. Bush pushes his plan for private Social Security accounts, the less the public seems to like it. When he first raised the issue, during his 2000 presidential campaign, 70% of respondents favored the idea, according to a poll then by the Pew Research Center.

Now, after a series of presidential appearances booming the plan, the Pew Center’s most recent poll shows public support at 46%. Bush Cabinet members are fanning across the country in a 60-day publicity blitz, and by the time they’re done, if present trends continue, support will have dropped into the high teens.

The public may have grasped the essential flaw in Mr. Bush’s sales pitch. Private accounts, according to Bush, are necessary most of all to correct Social Security’s actuarial imbalance. Yet he’s been unable to show how diverting money from the system into private accounts will balance the books.

Look at that Pew poll: Among supporters of private accounts, only 20% like the idea because it will “make Social Security more secure.”

By contrast, 52% of supporters favor the idea because it “will give individuals greater control” of their future.

If Mr. Bush wants to regain the offensive, he’ll have to reframe his sales pitch in that direction – stressing individual empowerment rather than actuarial responsibility.

Sensing the public’s ambivalence, congressional Democrats have gone into the legislative equivalent of a dead-man’s float. Their model here is the Republican opposition to the Clinton administration’s proposed reform of the U.S. health care system in 1993.

At first a few moderate Republicans in Congress made a stab at compromise with the Clinton proposal. Then GOP disciplinarians cracked down. They sensed, correctly, that a compromise of any kind would lead to a major Democratic victory.

Without engagement across the aisle, the united Democratic front split into bickering factions, and the plan collapsed within a year of its unveiling – a victim of its own complexity, public indifference, and Republican obstinacy.

According to an informal survey by the Washington Post last week, at least 42 of 44 Democratic senators say they will refuse to support any version of Mr. Bush’s plan for private accounts – more than enough to block a vote on the Senate floor.

Predictably enough, cracks are already showing in the facade of Republican support. It’s 1993 all over again, in reverse.

Republicans no less than Democrats have been struck by the lack of public support for Mr. Bush’s plan. Among conservatives of a libertarian bent, the hesitancy to embrace the proposal is philosophical as well as political.

As a way of disentangling individuals from the welfare state, Mr. Bush’s idea has serious flaws. The reasoning goes like this:

On the one hand, citizens are smart and responsible enough to control their own retirement funds, which is why they deserve private accounts.

On the other hand, the investments allowed for the private accounts, and the pace at which an account-holder can withdraw those “private” funds, will be strictly controlled by the government – because, presumably, citizens aren’t smart and responsible enough to control their own retirement funds.

Indeed, Mr. Bush’s plan may very well flood the securities markets with investment money that is strictly regulated, placing vast chunks of those markets under Washington’s control.

This is hardly the way to strike a blow at the welfare state, as Mr. Bush’s Republican allies are slowly realizing. Together with a wily Democratic opposition and a wary public, they form an excellent brick wall – or whatever metaphor you care to use.

Mr. Ferguson is a columnist for Bloomberg News.