Yes, sir, we've just had our 70 fat years in America, thanks to the Greatest Generation and the bounty of freedom and prosperity they built for us. And in these past 70 years, leadership — whether of the country, a university, a company, a state, a charity, or a township — has largely been about giving things away, building things from scratch, lowering taxes or making grants.

But now it feels as if we are entering a new era, “where the great task of government and of leadership is going to be about taking things away from people,' said the Johns Hopkins University foreign policy expert Michael Mandelbaum.

Indeed, to lead now is to trim, to fire or to downsize services, programs or personnel. We've gone from the age of government handouts to the age of citizen givebacks, from the age of companions fly free to the age of paying for each bag.

Let's just hope our lean years will only number seven. That will depend a lot on us and whether we rise to the economic challenges of this moment. Our parents truly were the Greatest Generation. We, alas, in too many ways, have been what the writer Kurt Andersen called “The Grasshopper Generation,' eating through the prosperity that was bequeathed us like hungry locusts. Now we and our kids together need to be “The Regeneration' — the generation that renews, refreshes, re-energizes and rebuilds America for the 21st century.

President Obama's bad luck was that he showed up just as we moved from the fat years to the lean years. His calling is to lead The Regeneration. He clearly understands that in his head, but he has yet to give full voice to it. Actually, the thing that most baffles me about Mr. Obama is how a politician who speaks so well, and is trying to do so many worthy things, can't come up with a clear, simple, repeatable narrative to explain his politics — when it is so obvious.

Mr. Obama won the election because he was able to “rent' a significant number of independent voters — including Republican business types who had never voted for a Democrat in their lives — because they knew in their guts that the country was on the wrong track and was desperately in need of nation-building at home and that John McCain was not the man to do it.

They thought that Mr. Obama, despite his liberal credentials, had the unique skills, temperament, voice and values to pull the country together for this new Apollo program — not to take us to the moon, but into the 21st century.

Alas, though, instead of making nation-building in America his overarching narrative and then fitting health care, energy, educational reform, infrastructure, competitiveness and deficit reduction under that rubric, the president has pursued each separately. This made each initiative appear to be just some stand-alone liberal obsession to pay off a Democratic constituency — not an essential ingredient of a nation-building strategy — and, therefore, they have proved to be easily obstructed, picked off or delegitimized by opponents and lobbyists.

So “Obamism' feels at worst like a hodgepodge, at best like a to-do list — one that got way too dominated by health care instead of innovation and jobs — and not the least like a big, aspirational project that can bring out America's still vast potential for greatness.