Health care may not end up being President Obama's biggest failure after all.

And his oft-repeated "if you like it you can keep it" pledge about health care plans may not turn out to be his most consequential broken promise.

Each may be far outdone by the fact that he is disillusioning a whole new generation and more of Americans.

From the start, they wanted to believe in his defining promise of "hope and change." They wanted to believe in politics and politicians again.

Millions of younger Americans — and many not so young — wanted and needed so much to believe in him only to conclude, finally, that they can't.

As Maureen Dowd wrote some time ago about the president, "He came as a redeemer and ...didn’t redeem," adding that "nothing bums out a nation ... like a self-appointed messiah who disappoints."

The polls would make it seem that millions see it as Dowd saw it. And millions, it seems, have lately answered for themselves Obama's own question from his first campaign. Many have concluded that, yes, it was all "just words."

In 1980, not long after he famously declared in the New York Times that "of a sudden, the GOP has become a party of ideas," the late Democratic Sen. Daniel Patrick Moynihan issued a less well-remembered clarification.

In the old Washington Star, he suggested that ideas don't really matter so much; experience does.

A younger man could perhaps be forgiven back then for seeing some humor in this apparent pre-election backtracking.

(Likely, Moynihan was taking some considerable heat from his Democratic colleagues for his election-year praise of Republicans).

But an older man now could scarcely be forgiven if he also failed to see the wisdom in it. Experience, as we are being daily reminded by this White House, really does count because, so often, with experience comes judgment.

And without it? Well, for one recent example, a more experienced president might have made some very different judgment calls on rhetoric like "red lines" and subjects like Syria.

And for another, he might have followed the advice of those like his then-chief of staff, who reportedly told him that a party line vote was precisely the wrong way to go in passing legislation as sweeping as Obamacare.

Apparently seeking to avoid the Clinton mistake of drafting a bill behind closed doors and alienating Congress in the process, Obama did the opposite, delegating so much to Democratic congressional leaders Harry Reid and Nancy Pelosi that he all but guaranteed there would be no meaningful consultation, much less any real collaboration, with the GOP — and, consequently, that there'd be little support if (when) the going got rough.

Moynihan could have told him, as he reportedly told the Clintons, that grand and ambitious legislative programs such as total reform of the nation's health care system must "pass 70-30 or they fail."

Even without Moynihan's counsel, more experience might have informed the president that his legislative strategy was flawed and went against Jefferson's better judgment.

"Great innovations," our third president said, "should not be forced on slender majorities" (nor, we might add, partisan ones). It may not be all that great an idea, but Obamacare is undeniably an innovation.

But then, ideas don't really matter so much; experience does. Well, OK, that's not exactly what Moynihan wrote in the summer of 1980.

What he wrote, exactly, was this: "We Democrats may be short on ideas of late, but we, at least, remain close to and accessible to experience."

Who thinks he would write that these days? Who thinks he'd write that about Barack Obama and today's Democratic Party — or the promise that massive changes to the country's health care system could leave health care plans and doctor-patient relationships unchanged — at least for all those who liked what they had? That hardly seems a promise uttered by a voice of experience.

What Moynihan seemed to be reaching for in that 1980 essay was a rationale for the re-election of Jimmy Carter and the presidential defeat of a Republican Party that had become "serious about ideas."

While that rationale proved a reach beyond his grasp, there was — as usual for Moynihan — much wisdom in what he wrote.

He offered advice for Democrats on what he called "matters that have been understood for some time and which we would do well to hold on to."

For one such example — timely, perhaps, as today's headlines — he wrote, quoting Roscoe Conkling, "When Doctor Johnson declared that patriotism is the last refuge of a scoundrel, he underestimated the potential of reform."

And for another bit of timely advice — and the president would have done well to heed it — there was the maxim Moynihan called "Al Smith's first principle."

It was, simply, this: "Never promise anything you can't deliver."

Michael E. Baroody Sr. is an Alexandria, Va., resident.