It’s as if, in his second inaugural speech, President Barack Obama understood deep down that he has won — not only elected in 2008 but re-elected in 2012 under the worst political circumstances facing an incumbent in decades.

He won, and as if he felt the weight of history more now, Obama stood at the Capitol and used the enduring themes of America’s history, on the day honoring Martin Luther King Jr., as starting points for an address that called for Americans to unite in pursuit of a brighter future.

Let others be terrified of foreign competition, or concerned that America’s values aren’t up to the challenges of the 21st century. “We are made for this moment,” Obama said, in large part because of the liberating movements of the past from Washington’s days and Lincoln’s days and Dr. King’s days.

Diversity was no better exemplified than by the Italian cap jauntily worn by Justice Antonin Scalia, but also marked by all the firsts that history will remark upon, from a gay Cuban-American poet delivering an inaugural poem, to Sonia Sotomayor, the first Latina justice, swearing in Vice President Joe Biden.

The first invocation of gay marriages will be noted: “Our journey is not complete until our gay brothers and sisters are treated like anyone else under the law — for if we are truly created equal, then surely the love we commit to one another must be equal as well,” Obama said.

As much as anything, though, “this moment” was significantly different from the inaugural of four years ago. Then, Obama was somber in the wake of the dramatic economic collapse that was to shadow the nation for the new president’s entire first term.

This year was about getting on with things — not only with the diversity symbolism and social liberalism, but with the growth and dynamism that America’s future needs and deserves.

“We understand that outworn programs are inadequate to the needs of our time,” Obama said. “So we must harness new ideas and technology to remake our government, revamp our tax code, reform our schools, and empower our citizens with the skills they need to work harder, learn more, reach higher. But while the means will change, our purpose endures: a nation that rewards the effort and determination of every single American.”

“That is what this moment requires,” he said. “That is what will give real meaning to our creed.”

But if Obama’s rhetoric soared, he also spoke to the gridlocked members of Congress all around him: Political victories are “only partial,” and they cannot be stymied by those who “mistake absolutism for principle, or substitute spectacle for politics, or treat name-calling as reasoned debate.”

If the president’s remarks meant anything, it was that while Obama understood at least the completeness of his November victory, he also understood that he would have to seek, and soon, some partial victories in a Capitol where compromise is in historically short supply.