Now we know what he means by "the audacity of hope."

In the face of a nation mired in economic gloom, President Obama cast an optimistic, even defiant note: "We will rebuild, we will recover, and the United States of America will emerge stronger than before," he told a joint session of Congress Tuesday, to cheers and applause.

Then Obama laid out his ambitions not only to lift the country out of its immediate crisis, but to build a sustainable future. He would double the nation's supply of renewable energy in three years. Find a cure for cancer. "Not wait another year" to provide comprehensive health care reform. Have America boast the highest proportion of college graduates in the world by 2020. Cut the $1.2 trillion budget deficit in half even as government spends billions for economic stimulus. Save or create 3.5 million jobs. Not to mention rescue the nation's banks, automakers and homeowners, get out of Iraq and defeat al Qaida.

It may seem like too much, too soon, from a young untested president. And without more details on how all this will be accomplished in a worsening economy, it's easy to be skeptical. His plans for rescuing the nation's banking system and credit markets remain uncomfortably vague; it's not surprising those sectors, so critical to economic recovery, have shown little forward progress.

But Obama is right about several things: First, when we were prospering, we failed to prepare for the future. Second, the nation's dire straits demand sweeping, long-term solutions that will position the country for future prosperity.

He is also right that healthcare costs, for individuals and businesses, is oppressive and a drag on the economy. Reform is critical, now. Investing in infrastructure, especially with renewable energy, is long over-due. And providing more help to states to improve education, particularly for early childhood and the college-bound, will lay the foundation for a workforce that can compete in 21st-century global markets.

Obama's agenda is vastly ambitious, but it's a match for the problems facing the nation today. It should also serve as a guide for state and local governments as they decide how to best invest the economic stimulus money. The future will be what we make it; in that, there is still good reason for audacious hope.