WASHINGTON, D.C. — Barack Obama publicly took the oath of office for his second term Monday, strongly defending the ideology of his party as he urged Americans to accept compromise as a path toward solving the nation’s problems.

“Progress does not compel us to settle centuries-long debates about the role of government for all time — but it does require us to act in our time,” Obama said, soon after taking the oath from Chief Justice John G. Roberts Jr. “Decisions are upon us, and we cannot afford delay. We cannot mistake absolutism for principle, or substitute spectacle for politics, or treat name-calling as reasoned debate.”

While just over 18 minutes — relatively short by historical standards — the address hit several major policy priorities Obama hopes to pursue.

For the first time, an inaugural address mentioned the rights of gay Americans, as Obama declared that America’s “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.”

The president also insisted on the need to “respond to the threat of climate change” — a subject he largely avoided after a stinging loss in Congress early in his first term.

“Some may still deny the overwhelming judgment of science, but none can avoid the devastating impact of raging fires, and crippling drought, and more powerful storms,” he said. “The path towards sustainable energy sources will be long and sometimes difficult. But America cannot resist this transition; we must lead it.”

“That is how we will preserve our planet, commanded to our care by God.”

Obama wove those specific policy pledges, along with brief reminders of his proposals for gun control and immigration reform, into a text that, overall, amounted to a strong reaffirmation of the core of liberal, Democratic politics and its belief in the positive role that government can play in the nation’s life.

In a nod to those who do not share that outlook, he noted that Americans “have never relinquished our skepticism of central authority, nor have we succumbed to the fiction that all society’s ills can be cured through government alone.”

But, he said, “preserving our individual freedoms ultimately requires collective action.”

“We do not believe that in this country, freedom is reserved for the lucky, or happiness for the few,” he said. “The commitments we make to each other — through Medicare, and Medicaid, and Social Security — these things do not sap our initiative; they strengthen us. They do not make us a nation of takers; they free us to take the risks that make this country great.”

“We are true to our creed when a little girl born into the bleakest poverty knows that she has the same chance to succeed as anybody else, because she is an American, she is free, and she is equal, not just in the eyes of God but also in our own,” he declared.

At the conclusion, Obama walked back into the Capitol building, then turned for a moment to look out at the national Mall, filled with hundreds of thousands of flag-waving Americans. “I want to see this again,” he could be heard saying.

Soon afterward, he signed the Capitol’s guest book, then, with the bipartisan congressional leadership looking on, signed the formal paperwork to submit the nominations of his choices for several Cabinet posts, the Secretaries of State, Defense and Treasury and the head of the CIA.

The speech culminated a ceremony heavily laced with references to the country’s long struggle toward equality for its African American citizens.

From an invocation by the widow of a slain leader of the civil rights movement that opened the formal proceedings, to the two Bibles on which Obama took the oath, one of which belonged to Abraham Lincoln and the other to the Rev. Martin Luther King Jr., the symbols of the nation’s 57th inaugural ceremony traced the historic arc that led toward the nation’s first black president.

Four years ago, Obama took office with the country in the midst of two wars and the worst economic crisis in more than half a century. His second inauguration arrives with one war over, the other winding down and the economy recovering, but with Washington dominated by a bitter political stalemate that reflects a deep partisan divide in the nation.

The inaugural ceremonies, themselves, highlighted the idea of bipartisanship and continuity of American democracy. Two of Obama’s predecessors, Democrats Bill Clinton and Jimmy Carter, were among the dignitaries gathered at the Capitol’s West Front. So, too, were many of the congressional Republicans who have battled Obama through the past four years. The country’s two living former Republican presidents, George H.W. Bush and George W. Bush were not present; the elder Bush recently was recently released from a hospital in Houston after a bout with bronchitis.

House Majority Leader Eric Cantor, R-Va., said before the ceremony that he expected most Republicans to attend the inaugural ceremony, a historic moment regardless of party. He noted that he had prime seats for Obama’s first inaugural and regretted not snapping any photos of the proceedings. “I’m going to try to this time,” he said.

Rep. Steve King, R-Iowa, a fiery conservative, said “my thought for today is, this is a constitutional event and our forefathers would be proud we’re following the directions they gave us.”

“Tomorrow we’ll start the political discussion.”

Overall, of course, the crowd, as is typical with inaugural celebrations, was heavily dominated by the president’s supporters, who cheered loudly as Obama’s motorcade arrived at the Capitol from the White House. They cheered again as the Obamas’ daughters, Malia and Sasha, were introduced and then, a few minutes later, for first lady Michelle Obama.

In keeping with the intense enthusiasm that Obama’s presidency has generated among African-Americans, the audience was disproportionately black. Several spectators commented on the special significance of the swearing-in taking place on the nation’s Martin Luther King Jr. day observance.

“It’s particularly special that today is the MLK holiday,” said David Anderson, 43, who traveled from Tampa, Fla. “It’s kind of predestined. You can’t get better than that.”

Ed Jennings, 44, who sported a knitted Obama cap, said he anticipated the president would urge unity in his inaugural address.

“It’ll be a summary of where this country is. There was a fierce debate about where our country is going, and he won,” he said.

Hazel Carter, 90, of Springfield, Ohio, attended the last inauguration and wasn’t going to miss this one. “I prayed, God, just let me keep breathing until the inauguration,” she said with a laugh.

“The crowd isn’t nearly the crowd of the first time. The anticipation isn’t what it was,” she said. “It’s a little more subdued, but beautiful. Beautiful. I love it.”

Seated next to her, Thelma Lawson, 61, a nurse from Chicago, said she had not attended the swearing-in four years ago, “but now I am so excited because I’m in the midst of what is history of being made twice.”

Chinwe Aldridge of Fort Washington, Md., said she and her husband had not decided to come to the ceremony until Sunday night, after some prodding from their two children.

“I told them we could have a better shot at home on television,” she said. “They said they had to be here. Those are big words from little kids.”



McCLATCHY-TRIBUNE Washington Bureau reporters Rich Simon, Melanie Mason, Lisa Mascaro and Joe Tanfani contributed to this article.