“I think this is going to be a tough game,” Mr. Obama said in a pre-game interview with NBC’s Matt Lauer. Pressed on who he’s rooting for, Mr. Obama told Mr. Lauer with a smile, “You’re not going to get me.”

The president, a Chicago Bears fan who unabashedly rooted for the Pittsburgh Steelers in the 2009 Super Bowl, instead offered a diplomatic take on the championship game.

Mr. Obama said the New York Giants and New England Patriots – both from solidly blue parts of the country – each “have their weaknesses.” He praised the Giants’ comeback this year as “pretty remarkable,” and the Patriots, he said, are “always tough” even though their defense is a “little shaky.”

Mr. Obama plans to watch the game with his wife and daughters at the White House.

His full interview with Mr. Lauer is set to air Monday morning.

Mr. Obama, in an interview with NBC that aired Sunday evening, said his administration will “do everything we can” to keep Iran from acquiring a nuclear weapon, while warning that military action would have an adverse impact on U.S. economic and security interests.

“I don’t think that Israel has made a decision on what they need to do. I think they, like us, believe that Iran has to stand down on its nuclear weapons program,” Mr. Obama said.

“Our goal is to resolve this issue diplomatically, that would be preferable,” Mr. Obama said. “We’re not going to take any options off the table though. Obviously any kind of additional military activity inside the Gulf is disruptive and has a big effect on us. It could have a big effect on oil prices.”

Mr. Obama’s comments come as U.S. defense officials are growing increasingly concerned that Israel will launch military strikes against Iran’s nuclear infrastructure.

The president declined to discuss details of his administration’s discussions with the Israelis, but said the two countries have been engaged in “closer military and intelligence consultation” than ever before.

“My No. 1 priority continues to be the security of the United States, but also the security of Israel, and we are going to make sure that we work in lock step as we proceed to try to solve this, hopefully diplomatically,” he said.

Meanwhile, he said Tehran is “feeling the pinch” of economic sanctions by the U.S. and others.

According to polls conducted across the state of voters as they entered the Nevada caucuses, a quarter of voters were Mormon — and 88% of them voted for the former Massachusetts governor. But perhaps more surprising was the fact that Mr. Romney won 46% of voters who described themselves as “very conservative,” a sizable advantage over the 25% who backed Mr. Gingrich.

Even strong supporters of the tea party gave Mr. Romney the edge, 35% to Mr. Gingrich’s 32%. Evangelical Christians favored him over Mr. Gingrich 43% to 28%.

The polls identified only a few weak spots in Mr. Romney’s across-the-board victory. Amid complaints from his critics that he cares too little about the poor, voters earning less than $30,000 a year favored Mr. Gingrich over Mr. Romney 32% to 29%. Independent voters in Nevada, as in other states where non-Republicans are allowed to participate, favored Texas Rep. Ron Paul with 46%; Mr. Romney got 28% of their vote, Mr. Gingrich 17%.

Another group that gave Mr. Romney a big thumbs down were the 18% of voters who said the most important quality they were looking for was that the candidate be a “true conservative” — only 4% of them supported Mr. Romney.

But far more voters, 43%, said their priority was to nominate a candidate who would beat President Barack Obama. Of those voters, 70% backed Mr. Romney.

“There’s a lot of people not satisfied with any of the candidates out there,” the Texas congressman said Sunday on ABC’s “This Week with George Stephanopoulos.” “And that’s why in many ways we’re seeing a lower turnout right now.”

Fewer voters came out in Nevada and Florida than four years ago, when Mr. Paul attempted to challenge eventual nominee John McCain and this year’s front-runner Mitt Romney.

Mr. Paul said Republicans are wondering why they haven’t been offered someone else besides Mr. Romney and former House Speaker Newt Gingrich.

“That’s what I’m trying to change,” Mr. Paul said on ABC.

The congressman said he plans to continue the race. He was campaigning in Minnesota on Saturday even as votes were tallied in Nevada.

“We have three or four caucus states that we believe our numbers are doing pretty good, so we have to just wait and see and continue to do exactly what we’re doing,” he said.

“Our goal is to get to Super Tuesday where we’re in much more favorable territory,” Mr. Gingrich said on NBC’s “Meet the Press,” pointing to primary voting in several southern states in early March.

After Texas’ primary in early April, “we’ll be very, very competitive in delegate count,” the former house speaker said.

On CBS’s “Face the Nation” Sunday, Mr. Gingrich answered questions about how he will adequately campaign in the next few weeks, a period during which there won’t be any Republican debates to help him reach a broad audience.

He agreed he lacks the organization and money of better-funded Mitt Romney, but said “we do have a lot of popular support and a pretty big grass-roots movement in every state,” he said. That, along with his “bold” plans to address taxes, social security for young people and welfare in states, should be a good foundation to “focus on the very big differences” between him and Mr. Romney, he said.

“My goal will be to show there’s a way to change Washington to get us on the right track that’s different from Obama and Romney,” he said, criticizing Mr. Romney’s job creation record as Massachusetts governor and his recent comment that he’s not concerned about the poor because they have safety nets.

Mr. Gingrich said the existing safety net is a “spider web” that traps the poor at the bottom.

Republicans will lose in the fall if they nominate a more moderate candidate like Mr. Romney, he said, citing Arizona Sen. John McCain’s loss to President Barack Obama is 2008.

Mr. Romney’s supporters say he is the best choice in November.

Mr. Romney is “winning every segment of the Republican base,” Virginia Gov. Bob McDonnell, a Republican, said Sunday on CNN’s “State of the Union.” “He’s got the best chance to beat President Obama.”

“There is not going to be that enthusiasm among the base” for Mr. Romney, said Tony Perkins, president of the Family Research Council, a conservative Christian organization.

“The focus now is on the House and the Senate and expanding conservative majorities” in Congress, he said Sunday on CNN’s “State of the Union,” suggesting some conservatives are growing weary of the presidential primary fight and turning their attention to congressional races.

Mr. Perkins headed a meeting of social conservative leaders in Texas last month that backed Rick Santorum’s campaign. But after a strong showing in Iowa, Mr. Santorum has struggled. He finished a disappointing fourth in Saturday’s Nevada caucuses.

Mr. Perkins said Mr. Romney was preferable to President Barack Obama, but added that it could take until the Republican convention to see support for Mr. Romney solidify among social conservatives.

Former Republican House Majority Leader Dick Armey also showed tepid support for Mr. Romney, but conceded that the ex-Massachusetts governor appears likely to take the nomination.

“We’re not going to get a reliable, small-government conservative out of this nominating process,” Mr. Armey said on CNN. Mr. Armey is chairman of FreedomWorks, an organization that has aligned itself with tea-party supporters.

Mr. Armey said he doesn’t see former House Speaker Newt Gingrich, who appears to be fading, building fresh momentum as the Republican primary race continues.

Mr. Gingrich is “taking a second-rate campaign and turning it into a first-rate vendetta,” said Mr. Armey, who was a Republican leader alongside Mr. Gingrich in the 1990s. “I don’ t think Newt will be able to replicate that magic moment he had in South Carolina.”

Mr. Paul, speaking to reporters following a rally before an estimated 1,500 at Bethel University, said there was “no doubt” that his campaign has gained more traction than in 2008. While he would need to win outright some states to achieve the nomination, Mr. Paul said he is more focused on picking off delegates for the Republican National Convention.

“I want to maximize delegates, and so far we’ve been able to pick up delegates,” Mr. Paul said following the third of three overflow events in Minnesota, which holds its caucus votes on Tuesday evening.

A test for Mr. Paul’s campaign came earlier on Saturday, when Nevada Republicans caucused in a state where the Texas Republican came second in 2008. Mr. Paul said preliminary reports from Nevada suggested another second place finish, though he acknowledged former Massachusetts Gov. Mitt Romney was out of reach.

“We are planning on getting some delegates out of Nevada, the number is uncertain yet and later tonight we’ll know,” he said.

Mr. Paul weighed in on a range of issues during his stump speech, which was well received by a crowd that was noticeably younger than at some of his other events. The long-time critic of the Federal Reserve lambasted the central bank and chairman Ben Bernanke, suggesting Mr. Bernanke “literally laughs” at people who suggest record-low interest rates are hurting consumers who seek to build their savings.

Additionally, he said the Fed and the U.S. routinely mislead the public.

“They lie and fib to us, they say there’s no inflation. Nobody believes it’s only 2% inflation; if it even is 2%, who has the right to steal 2% of your money every year?” Mr. Paul told the crowd.

He added, “The unemployment figures and the inflation figures are all deception.”

Mr. Paul also suggested he agreed with the decision by China and Russia to veto a U.N. Security Council resolution condemning violence in Syria. Violence in Syria, which has grown in recent days, is a “neighborhood problem,” Mr. Paul said, suggesting it would not be appropriate for the United Nations to engage in the region.

“I’m delighted things are getting better. I think they are,” Mr. Romney told a crowd packed into a metal fabrication plant here. But instead of giving any recognition to Mr. Obama, he said the credit belonged to businessmen like the owner of the plant.

Amid signs of economic improvement, Mr. Romney is offering a broader buffet of options for attacking the president’s fiscal policies. On Saturday, he laid into Mr. Obama for his “crony capitalism,” dubbed the stimulus package a failure and warned that Washington’s borrowing was putting the nation on an unsustainable path.

“That stimulus he had, it did not do the job,” Mr. Romney said. “That stimulus did not create private sector jobs like it should have, like it could have. It instead protected government jobs.”

Mr. Romney, who is heavily favored to win Saturday’s Nevada caucuses, also treated the western state to a fuller description of his time spent working for the 2002 Winter Olympics in Salt Lake City, an experience he often cites among his business successes.

“We were draped in scandal, I’ll tell ya, it was a real mess,” Mr. Romney said as he explained they needed to recruit some 25,000 volunteers for the games to run smoothly.

“As a volunteer you got no tickets to any events, alright, all you got was the uniform, you know the jacket and the leggings and so forth,” Mr. Romney said. “Seventeen days working in a parking lot directing traffic or on the side of a mountain, you know, smoothing down the snow for the skiers that would come along. That’s what you did.”

Mr. Romney said some 47,000 volunteers ultimately applied and chalked it up to Americans stepping up in a time of need.

With such little presence out West from Newt Gingrich, Mr. Romney has been silent on his chief GOP rival in recent days.

CHANHASSEN, Minn.–GOP presidential hopeful Rep. Ron Paul is attracting strong support at a series of rallies in Minnesota Saturday, and few lines of his stump speech are receiving more cheers than his call to repeal the Patriot Act and National Defense Authorization Act.

Mr. Paul, rallying voters ahead of Tuesday’s Minnesota caucuses, told supporters at an afternoon rally that these laws -– particularly the NDAA -– “is not what this country is about!” The sentiment, as it was in campaign stops earlier this week in Nevada, was met with hearty cheers from Mr. Paul’s backers, many of whom were turned away or forced to listen from outside the venue on a brisk winter afternoon.

With a libertarian platform focused on reducing the influence of the federal government and boosting individual rights, Mr. Paul is a natural adversary for the more invasive provisions in the Patriot Act and NDAA. The latter especially is a frequently yelled slogan at Mr. Paul’s event, typically with a derisive sneer or as a rallying cry for supporters.

The NDAA, signed by President Barack Obama on New Year’s Eve, includes a provision giving the government the power to indefinitely detain any terror suspect captured on U.S. or foreign soil, even if that person is a U.S. citizen.

“The president can use the military to arrest American citizens, they don’t have to be charged, they don’t have to be tried,” Mr. Paul explained to a standing-room-only crowd in Rochester, Minn., earlier on Saturday. “If that stands there’s not much left to our American civil liberties … if we can watch that and not do something about it the future looks bleak.”