President Obama, setting out Monday on a tour of Midwestern towns, called on lawmakers to stop their "partisan games" as he tried to connect with voters over frustration with Washington.

On a trip tinged with campaign-season politics, Obama lambasted what he described as the "brinkmanship" in the capital. He said the country's "broken" politics are exacerbating its economic problems. And, amid an accelerating debate over entitlement spending, the president vowed to protect Social Security for generations to come.

"I know you're frustrated. And I'm frustrated too," Obama said, during a stop in Cannon Falls, Minn. But he also said that just because people are frustrated with the political system doesn't mean they should lose faith in the government's ability to confront the country's problems.

The president heads next to Iowa before finishing up in Illinois. In Minnesota, Obama struck a casual pose, speaking outside with his sleeves rolled up and collar unbuttoned.

Though the three-state tour is considered an official White House visit, Obama's mission to ease Americans' concerns about their jobs could have the added effect of helping him keep his own. The latest Gallup tracking poll showed the president's approval rating at an all-time low of 39 percent.

More On This...

White House Press Secretary Jay Carney told reporters Monday that Obama will not outline a specific economic proposal but will be listening to Americans' ideas about how to repair the economy. He said the president is visiting areas with relatively low unemployment to find out what's working.

With poll numbers falling for both Obama and Congress after a nasty political fight over raising the country's borrowing limit and spending cuts, Americans are in a bad humor. They are still feeling the deep pinch of a stunted recovery from the worst economic downturn since the 1930's Great Depression.

The country also suffered a blow to national pride as a major debt rating agency lowered its assessment of American credit worthiness for the first time in history. Unemployment stands above 9 percent.

The president will get a chance to absorb the public's anger and do his best to give optimistic answers as he motors between town hall stops.

In Iowa, Republican candidates for president just squared off for a high-stakes debate and straw poll.

But the White House pitched the trip as a purely official visit, and a chance for the president to hear from Americans about the economic climate.

Carney said Monday the trip had nothing to do with the straw poll.

Asked why the trip wasn't considered political, White House spokesman Josh Earnest said Friday that the president "views it as one of the chief responsibilities in office to spend some time outside Washington, D.C., talking to people all across the country about the economy and about how they're impacted by the policy decisions that he's making here in Washington, D.C."

Such visits, he said, are "something that a president should do." Earnest denied that the GOP activity in Iowa had anything to do with the trip, saying a "robust debate" about economic policies is taking place in that state and the other states Obama's visiting.

But Republicans suggested the president was merely campaigning on the taxpayers' dime. The Republican National Committee labeled the trip Obama's "Debt-End Bus Tour." A tongue-in-cheek RNC website called it: "A totally non-political taxpayer-funded administration event that just happens to criss-cross several battleground states critical to the president's reelection."

Obama was unlikely to engage any of his potential Republican rivals by name, aides said, but he's already indicated plans to draw sharp contrasts between his ideas on the economy and the Republican approach, which the president recently dismissed to little more than slashing spending on vital programs like education and Medicare, the program that provides health care for the poor.

At the same time, aides say that coming off a debt deal that included deep cuts without raising any taxes, the president is ready for complaints from disaffected Democrats tired of his compromises with Republicans, and from a public disgusted with a dysfunctional Washington.

The bus tour itinerary takes Obama through three states he won in 2008 but where he now needs to shore up his standing. In Iowa, Obama returns to a state that handed him a key victory over Democratic rival Hillary Rodham Clinton in 2008, but where Republicans have now been blanketing the state in preparation for its first-in-the-nation caucuses, attacking the president at every turn.

Obama made a similar outing last year, traveling the Midwest in a two-day, three-state tour in April 2010 that took him to Iowa, Illinois and Missouri. There was no bus, but the president's motorcade made hours-long drives through rural areas, passing school children waving American flags and seniors sitting on lawn chairs.

The trip gave the president a chance to engage in some of the grass roots politicking he perfected in 2008 during weeks spent campaigning in the small towns that would help carry him to victory in places like Iowa. Speaking to reporters aboard Air Force One on his way back to Washington, Obama said the trip reminded him of his early days in politics.

"It was a reminder that sometimes there's a mismatch between the way politics are portrayed in Washington and how people are feeling," the president said at the time. "I think it's a less toxic atmosphere."

But the political fumes of the weekend Republican straw poll and subsequent Sunday campaigning will still hang heavy over Iowa.

Rep. Michele Bachmann and Texas Gov. Rick Perry competed for the hearts and minds of conservative Iowa voters Sunday night, focusing on jobs at the same event in what might be a preview of the months ahead in the Republican race to find a challenger to Obama.

Perry and Bachmann were vying for attention as their campaign schedules put them at the same county Republican Party event in Waterloo, Iowa.

The Associated Press contributed to this report.