More and more lately, I find people asking me: What do you think President Obama really believes about this or that issue? I find that odd. How is it that a president who has taken on so many big issues, with very specific policies — and has even been awarded a Nobel Prize for all the hopes he has kindled — still has so many people asking what he really believes?

I don’t think that President Obama has a communications problem, per se. He has given many speeches and interviews broadly explaining his policies and justifying their necessity. Rather, he has a “narrative” problem.

He has not tied all his programs into a single narrative that shows the links between his health care, banking, economic, climate, energy, education and foreign policies. Such a narrative would enable each issue and each constituency to reinforce the other and evoke the kind of popular excitement that got him elected.

Without it, though, the president’s eloquence, his unique ability to inspire people to get out of their seats and work for him, has been muted or lost in a thicket of technocratic details. His daring but discrete policies are starting to feel like a work plan that we have to slog through, and endlessly compromise over, just to finish for finishing’s sake — not because they are all building blocks of a great national project.

What is that project? What is that narrative? Quite simply it is nation-building at home. It is nation-building in America.

I’ve always believed that Mr. Obama was elected because a majority of Americans fear that we’re becoming a declining great power. Everything from our schools to our energy and transportation systems are falling apart and in need of reinvention and reinvigoration. And what people want most from Washington today is nation-building at home.

Many people, including conservatives, voted for Barack Obama because in their hearts they felt he could pull us all together for that project better than any other candidate. Many are what I’d call “Warren Buffett centrists.” They are not billionaires, but they are people who believe in Mr. Buffett’s saying that whatever he achieved in life was due primarily to the fact that he was born in this country — America — at this time, with all of its advantages and opportunities.

I believe that. And I believe that without a strong America — which, at its best, can deliver more goods and goodness to its own citizens and to the world than any other nation — our kids and many others around the world will not have those opportunities.

I am convinced that this kind of nation-building at home is exactly what Mr. Obama is trying to deliver, and should be his unifying call: We need universal health care because it would strengthen our social fabric and enable our businesses to better compete globally. We need to upgrade our schools because no child in 21st-century America should be left behind and because we cannot compete for the best new jobs without doing so. We need a greener economy, not just to mitigate climate change, but because a world growing from 6.7 billion people to 9.2 billion by 2050 is going to demand more and more clean energy and water, and the country that develops the most clean technologies is going to have the most energy security, national security, economic security, innovative companies and global respect.

But to deliver this agenda requires a motivated public and a spirit of shared sacrifice. That’s where narrative becomes vital. People have to have a gut feel for why this nation-building project, with all its varied strands, is so important — why it’s worth the sacrifice. One of the reasons that independents and conservatives who voted for Mr. Obama have been so easily swayed against him by Fox News and people labeling him a “socialist” is because he has not given voice to the truly patriotic nation-building endeavor in which he is engaged.

“Obama’s election marked a shift — from a politics that celebrated privatized concerns to a politics that recognized the need for effective government and larger public purposes. Across the political spectrum, people understood that national renewal requires big ambition, and a better kind of politics,” said the Harvard political theorist Michael Sandel, author of the new best seller — “Justice: What’s the Right Thing to Do?” — that calls for elevating our public discourse.

But to deliver on that promise, Sandel added, Obama needs to carry the civic idealism of his campaign into his presidency. He needs a narrative that will get the same voters who elected him to push through his ambitious agenda — against all the forces of inertia and private greed.

“You can’t get nation-building without shared sacrifice,” said Sandel, “and you cannot inspire shared sacrifice without a narrative that appeals to the common good — a narrative that challenges us to be citizens engaged in a common endeavor, not just consumers seeking the best deal for ourselves. Obama needs to energize the prose of his presidency by recapturing the poetry of his campaign.”