WASHINGTON -- A confident President Barack Obama is expected Tuesday to unveil an aggressive agenda in the first State of the Union address of his second term, calling for a rewrite of the nation’s outdated immigration laws, steps to prevent gun violence and ways to bolster a still fragile economy.

Obama starts his second term with job approval ratings among the highest since he took office. But he faces a not-yet-recovered economy, a mounting deficit, an often hostile Congress and a nation increasingly distrustful that polarized, partisan Washington can get anything done.

In many ways, the address serves as a marker for what the president hopes will form his legacy. After outlining his second-term agenda in an inaugural speech last month that infuriated Republicans for its full-throated embrace of liberalism, Obama will deliver details of what he wants to accomplish, priorities that include energy independence, education and job creation.

“A lot of people think the State of the Union is empty rhetoric, but it’s full of specific requests,” said Robert Lehrman, a former speechwriter for Vice President Al Gore and a communications professor at American University. “It’s not only the state of the union, but the state of the Obama administration.”

Tens of millions are expected to watch the 9 p.m. EST address, which Obama will deliver from the U.S. Capitol; in 2012, 38 million households tuned in. Sen. Marco Rubio of Florida, a rising star in his party who has garnered buzz as a possible 2016 presidential contender, will deliver the Republican response – in English and in Spanish.

Rubio has been leading an immigration overhaul in the Senate, but Republicans are eager for the conservative freshman to illustrate the party’s biggest point of contention with Obama: his stewardship of the economy.

This year’s speech marks the 100th anniversary of the State of the Union. Though George Washington was the first president to address Congress, speeches soon were scrapped in favor of the written word. Woodrow Wilson, however, reconstituted the in-person delivery to Congress in 1913, a custom that has continued ever since.

White House officials declined to divulge details, but Obama gave a preview of his remarks to House of Representatives Democrats on Thursday, telling them he’d talk about ensuring an economy that works for all.

“I’m going to be talking about making sure that we’re focused on job creation,” he said. “It means that we’re focused on education and that every young person is equipped with the skills they need to compete in the 21st century. It means that we’ve got an energy agenda that can make us less dependent on foreign oil, but also that we’re cultivating the kind of clean energy strategy that will maintain our leadership well into the future.”

In the months since he defeated challenger Mitt Romney, Obama already has waged battle with congressional Republicans over tax increases and spending reductions. Last week, he urged Congress to pass a package of modest cuts and tax changes as a way to delay what the government calls sequester cuts – drastic, across-the-board federal spending reductions that are scheduled to take effect March 1.

“We’re going to talk about, yes, deficits and taxes and sequesters and potential government shutdowns and debt ceiling,” Obama told House Democrats. “We’ll talk about that stuff, but all from the perspective of how are we making sure that somebody who works hard in this country – a cop, or a teacher, or a construction worker, or a receptionist – that they can make it if they work hard, and that their kids can make it and dream even bigger dreams than they have achieved.”