WASHINGTON - Pleading for unity in a newly divided government, President Barack Obama implored Democratic and Republican lawmakers to rally behind his vision of economic revival for an anxious nation, declaring in his State of the Union address Tuesday night: "We will move forward together or not at all."

The president unveiled an agenda of carefully balanced political goals: a burst of spending on education, research, technology and transportation to make the nation more competitive, alongside pledges, in the strongest terms of his presidency, to cut the deficit and smack down spending deemed wasteful to America. Yet he never explained how he would pull that off or what specifically would be cut.

Obama spoke to a television audience in the millions and a Congress sobered by the assassination attempt against one if its own members, Rep. Gabrielle Giffords. Her seat sat empty, and many lawmakers of competing parties sat together in a show of support and civility.

Yet differences were still evident, as when Democrats stood to applaud his comments on health care and tax cuts while Republicans next to them sat mute.

In his best chance of the year to connect with the country, Obama devoted most of his hour-long prime-time address to the economy, the issue that dominates concern in a nation still reeling from a monster recession - and the one that will shape his own political fortunes in the 2012 election.

Eager to show some budget toughness, Obama pledged to veto any bill with earmarks, the term used for lawmakers' pet projects. House Speaker John Boehner and other Republicans applauded. But Obama's promise drew a rebuke from his own party even before he spoke, as Senate Majority Leader Harry Reid, D-Nev., said the president had enough power and that plans to ban earmarks were "a lot of pretty talk."

Obama's proposals Tuesday night ranged across the scope of government: cutting the corporate tax, providing wireless services for almost the whole nation, consolidating government agencies and freezing most discretionary federal spending for the next five years. In the overarching theme of his speech, the president told the lawmakers: "The future is ours to win."

In essence, Obama reset his agenda as he heads toward a re-election bid with less clout and limited time before the campaign consumes more attention.

Yet Republicans have dismissed his "investment" proposals as merely new spending. Republican Rep. Paul Ryan of Wisconsin, giving the GOP's response, said the nation was at "a tipping point" leading to a dire future if federal deficits aren't trimmed. The Senate's Republican leader, Mitch McConnell of Kentucky, said the president had gotten the message from the November midterm elections and "changed the tone and the rhetoric from the first two years."

Obama entered the House chamber to prolonged applause and to the unusual sight of Republicans and Democrats seated next to one another rather than on different sides of the center aisle. And he began with a political grace note, taking a moment to congratulate Boehner, the new Republican speaker of the House.

Calling for a new day of cooperation, Obama said: "What comes of this moment will be determined not by whether we can sit together tonight but whether we can work together tomorrow."

On a night typically known for its political theater, the lawmakers sometimes seemed subdued, as if still in the shadow of the Arizona shootings.

Many in both parties wore black-and-white lapel ribbons, signifying the deaths in Tucson and the hopes of the survivors. Giffords' husband was watching the speech from her bedside, as he held her hand. At times, Obama delivered lighter comments, seeming to surprise his audience with the way he lampooned what he suggested was the government's illogical regulation of salmon.

Halfway through his term, Obama stepped into this moment on the upswing, with a series of recent legislative wins in his pocket.

and praise from all corners for the way he responded to the shooting rampage in Arizona. But he confronts the political reality is that he must to lead a divided government for the first time, with more than half of all Americans disapproving of the way he is handling the economy.

Over his shoulder a reminder of the shift in power on Capitol Hill: Boehner, in the seat that had been held by Democratic Speaker Nancy Pelosi.

Obama conceded that everything he asked for would prompt more partisan disputes. "It will take time," he said. "And it will be harder because we will argue about everything. The cost. The details. The letter of every law."

Obama used the stories of some of the guests sitting with his wife, Michelle, to illustrate his points, including a small business owner who, in the tradition of American ingenuity, designed a drilling technology that helped rescue the Chilean miners.

Flanking Mrs. Obama in the gallery: Brianna Mast, the wife of a soldier seriously injured in Afghanistan, and Roxanna Green, mother of the nine-year girl killed in the Tucson shooting.

The president cast the challenges facing the United States as bigger than either party. He said the nation was facing a new "Sputnik" moment, and he urged efforts to create a wave of innovation to create jobs and a vibrant economic future, just as the nation vigorously responded to the Soviets beating the U.S. into space a half century ago.

There was less of the see-saw applause typical of State of the Union speeches in years past, where Democrats stood to applaud certain lines and Republicans embraced others. Members of the two parties found plenty of lines worthy of bipartisan applause.

Yet as reaction flowed in, there was immediate blowback from all corners of the Democratic base. Environmentalists, trial lawyers, gay rights activists, labor leaders and Latino-rights groups all released statements, ranging from tepid to angry, complaining about everything from Obama's proposed spending freeze to his definition of clean energy.

In a speech with little focus on national security, Obama appeared to close the door on keeping any significant U.S. military presence in Iraq beyond the end of the year. "This year, our civilians will forge a lasting partnership with the Iraqi people while we finish the job of bringing our troops out of Iraq," the president said.

The president reiterated his call for a comprehensive immigration bill, although there appears little appetite for it Congress. Another big Obama priority that stalled and died in the last Congress, a broad effort to address global climate change, did not get a mention in the State of the Union. Nor did gun control or the struggling effort to secure peace in the Middle East.

Obama worked in a bipartisan shout-out to Vice President Joe Biden and Boehner as two achievers emblematic of the American dream, the former a working-class guy from Scranton, Pa., the latter once a kid who swept floors in his father's Cincinnati bar. Biden and Boehner shook hands over that, and Boehner, clearly moved, flashed a thumbs-up.

After dispensing with all the policy, the president ended in a sweeping fashion.

"We do big things," the president said. "The idea of America endures."

Associated Press writers Nancy Benac, Jim Kuhnhenn, Erica Werner and Darlene Superville contributed to this report.