“For now decisions are upon us, and we cannot afford delay,” he said. “We cannot mistake absolutism for principle, or substitute spectacle for politics, or treat name-calling as reasoned debate,” the president said. “We must act; we must act knowing that our work will be imperfect.”

In his second term, Obama faces a polarized political climate. He must address fiscal issues – tax revisions and spending cuts – and pressing international obligations: stopping Iran’s nuclear program, navigating an end to the war in Afghanistan and avoiding tensions with China over the administration’s “pivot” to Asia. In the weeks since he defeated Republican Mitt Romney, he’s already battled with Republicans in Congress over tax increases and spending reductions.

Outlining the nation he envisions, he sounded the themes of his recent campaign as a call for using the federal government to shift the benefits of the country and its economy to the poor and middle class and away from the wealthy.

“We, the people, understand that our country cannot succeed when a shrinking few do very well and a growing many barely make it,” he said. “We believe that America’s prosperity must rest upon the broad shoulders of a rising middle class.”

He connected past sacrifices to today’s struggles for equality: civil rights for gays, equal pay for women, economic equality for the poor.

“We, the people, declare today that the most evident of truths – that all of us are created equal – is the star that guides us still,” Obama said. “Just as it guided all those men and women, sung and unsung, who left footprints along this great Mall, to hear a preacher say that we cannot walk alone; to hear a King proclaim that our individual freedom is inextricably bound to the freedom of every soul on Earth.”

Republicans, who joined Obama at the White House in the morning for coffee and later at the Capitol for lunch, expressed hope that the two sides could work together on fiscal issues.

“The president’s second term represents a fresh start when it comes to dealing with the great challenges of our day; particularly, the transcendent challenge of unsustainable federal spending and debt,” said Senate Minority Leader Mitch McConnell, R-Ky. “Republicans are eager to work with the president on achieving this common goal, and we firmly believe that divided government provides the perfect opportunity to do so. Together, there is much we can achieve.”

The Obamas and Bidens started their day with a prayer service at St. John’s Episcopal Church a few blocks from the White House, where every president since James Madison has worshipped.

At the service, Pastor Andy Stanley of North Point Community Church in Alpharetta, Ga., told the story of Jesus moving from being the most powerful person in the room to a servant washing disciples’ feet and directing others to do the same.

“What do you do when in a position of power? You leverage that power for the benefit of other people in the room,” he said. “Mr. President, you have an awfully big room.”

A few hours later, Chief Justice John Roberts Jr. administered the 35-word oath – the same one recited by every American president since George Washington.– at the West Front of the Capitol, which was draped with red, white and blue bunting.