President Obama will attempt in Tuesday night's State of the Union address to build on the political capital he began to generate with a string of accomplishments in the lame duck session of Congress at the end of last year and the wide praise he received from both sides of the aisle for his speech in the aftermath of the shooting tragedy in Tucson.

With his approval rating on the rise, Obama faces a newly empowered Republican Party that is eager to challenge his agenda at nearly every turn but has also opened the door to a new level of cooperation with a president who has demonstrated a desire to slide toward the political center.

Obama will be aided by the symbolic gesture of Democratic and Republican lawmakers pairing off to mix up the traditionally partisan seating arrangements, as he tries to recapture the post-partisan tone that helped spring him into the presidency but was largely absent from his first two years in office.

"These are big challenges that are in front of us," Obama said in a video emailed to supporters over the weekend, which previewed his speech. "But we're up to it, as long as we come together as a people -- Republicans, Democrats, independents -- as long as we focus on what binds us together as a people, as long as we're willing to find common ground even as we're having some very vigorous debates, that's what built this country. That's what we're all about."

There are some recent indications that Obama may have an opportunity to find more common ground with Republicans.

Appearing on "Face The Nation" on Sunday, Sen. John McCain (R-Ariz.) -- who has been one of Obama's most frequent and vocal critics since losing to him in the 2008 election -- said that the president has "changed a great deal" and has wisely shifted toward a more centrist approach in the two years since he took office.

"I think he's doing a lot of right things -- this emphasis on cutting spending that we'll be talking about...was something that obviously was not talked about in the last two years," McCain said. "I think there's common ground because I think the president realized, as a result of the November elections, that the American people have a different set of priorities."

Bruce Buchanan, a professor of presidential and American politics at the University of Texas, suggested that Obama's tenor in reaching out to Republicans would be a particularly important indicator in Tuesday's speech.

"He somehow has to continue that Tucson tone," Buchanan said. "He hit a plateau there that worked for audiences all over the country, and to the extent you can in a speech about policy where you don't have the emotional opportunities he had in Tucson, he needs to try to keep that level of soaring effectiveness."

In his video previewing the speech, Obama said that he will zero in on rebuilding the economy -- the issue that defined the 2010 midterms and is likely to remain the most critical factor in his 2012 re-election campaign.

"My principle focus -- my number one focus -- is going to be making sure that we are competitive, that we are growing, and that we are creating jobs not just now but well into the future," Obama said. "And that is what's going to be the main topic of the State of the Union."

The address will offer Obama a chance to reach a vast television audience. However, in the past, the State of the Union has tended not to have a long shelf life, as subsequent event have quickly diminished its political significance.

Historical precedent suggests that Obama would be wise not to veer from the heart of his message in Tuesday's speech, according to Bruce Buchanan.

"What most presidents have done that I consider to have been a mistake is to try to cover too much in a State of the Union message, and so his model ought to be Reagan," Buchanan said. "Reagan would focus on two or three big things, rather than Clinton's 120 separate things, which sometimes left the audience confused about what the message was."

Even amid the potential for a revitalized political discourse that could include more cooperation between Democrats and Republicans, the partisan divide in Washington remains, in many ways, as visible as ever, and it will be on full display as the president wades into policy specifics on Tuesday.

Obama is expected to suggest increases in infrastructure spending to make America more economically competitive, even as he calls for taking additional steps to bring down the federal debt.

In an appearance on "Meet The Press" on Sunday, House Majority Leader Rep. Eric Cantor (R-Va.) said that members of his party would not go along with plans to raise the debt ceiling, which currently stands at over $14 trillion, without coinciding moves to shrink the federal budget immediately.

"Republicans are not going to vote for this increase in the debt limit unless there are serious spending cuts and reforms," Cantor said. "We know there are hundreds of programs that are going to need to be cut."