President Obama has a New Year’s resolution that will shape his reelection strategy at the dawn of 2012: Keep beating up on an unpopular Congress.

If that approach sounds much like the way the president ended 2011 — with a barnstorming tour and speeches evoking populist themes — that’s because the White House believes it hit upon a winning formula toward the end of a bruising, politically damaging year.

After taking his lumps during the summer’s bitter debt-ceiling debacle, Obama switched tactics, eschewing an “inside game” based on direct negotiations with Capitol Hill Republicans for an “outside game” focused on harnessing public opinion. It culminated two weeks ago when House Speaker John A. Boehner (Ohio) gave in under enormous public pressure and agreed to an Obama-backed, two-month extension of the payroll tax cut.

Administration aides say that Obama emerged from the showdown with public consensus that he, not Congress, is more willing to rise above Washington’s partisan gridlock. And as he enters his reelection campaign year, Obama intends to “double down” on his outside strategy, pressing the message that he is fighting for the middle class against a Congress beholden to special interests, aides said.

Obama’s decision to exploit his bitter divisions with Capitol Hill Republicans signals a shift from his 2008 campaign promise to soften the tone of debate in Washington and bridge the partisan divide, something the president has recently conceded could take longer than two terms in office. It also means his legislative agenda could grind to a near halt in this election year. White House aides said that Obama is willing to work with Congress if lawmakers refrain from “partisan attacks” but that after the February fight to extend the payroll tax holiday through the end of the year, the president will not engage in any more high-stakes showdowns to advance his policies before the election.

Obama will resume his nationwide jobs tour with an appearance in Cleveland on Wednesday, and his State of the Union address Jan. 24 will echo the populist themes the president laid out in a speech in Osawatomie, Kan., in early December.

“In terms of the president’s relationship with Congress in 2012 . . . the president is no longer tied to Washington,” deputy press secretary Josh Earnest said in Hawaii, where Obama is spending a 10-day vacation that ends Monday.

White House aides say that if Obama is not forced to engage Congress in regular partisan brinkmanship — “putting out fires,” as Earnest described it — the president will have a “larger playing field” to articulate a broader agenda for the nation as he heads into the election. The administration views the looming February fight over the payroll tax cut as the final “must-do” legislative initiative and the last potential “cliff-hanger” vote on Obama’s domestic jobs agenda.

After that, if Obama’s “playing field includes working with Congress, all the better,” Earnest said. “But I think my point is that that’s no longer a requirement.”

There is ample precedent for presidents to campaign against the legislature, including Harry Truman’s railings against a “do-nothing” Congress and Bill Clinton’s strategy in 1996 after Republicans had assumed control of both chambers two years earlier. Obama invoked Truman during a September speech in Detroit that kicked off his jobs tour.

Yet the strategy carries an inherent danger for the president, who risks being viewed as giving up on the legislative process in favor of politics long before Election Day. Obama still needs Congress’s support on other critical matters, such as installing several high-level appointees, including a pair of nominees to the Federal Reserve he announced last week.

And with unemployment still above 8 percent, Obama cannot afford to look as if he is out of big ideas. The White House is planning to roll out more in its series of “we can’t wait” small-scale economic initiatives that do not require congressional approval, but those might not be enough to convince voters that the president is doing everything he can to improve the economy.

“Perhaps the president is satisfied with the state of our economy, but Americans expect their elected leaders to work together to boost job creation — even in an election year,” Boehner spokesman Brendan Buck said Friday when asked about the White House strategy. “Divided government can be challenging, but that’s no excuse for him to put his presidency on autopilot when so many Americans are looking for work.”

There are signs that the boost in the polls that Obama enjoyed coming out of the payroll tax debate has evaporated. A Gallup poll last week showed his job approval rating back in the low 40s — where his ratings have hovered most of the fall. At the same time, Congress’s approval rating is at an all-time low, suggesting that both parties have been dragged down by the constant bickering. Also, Obama’s assault on Congress could wind up tarring Democratic legislators who are facing tough reelection campaigns.

“It’s really disappointing to hear that the president has already given up on tax reform, strengthening our energy security, making it easier for employers to hire or the basic operations of government,” said Don Stewart, a spokesman for Senate Minority Leader Mitch McConnell (Ky.).

Obama’s relationship with Boehner soured this past summer after the president tried, unsuccessfully, to negotiate a “grand bargain” to reduce the nation’s deficit by $4 trillion while at the same time boosting spending in the short term to spur the economy. After Boehner halted the talks and a potential default loomed, Obama was forced to accept a deal that trimmed the debt by $1.2 trillion and offered no new revenue for his spending proposals.

In December, Obama and Senate leaders forged an agreement on the two-month extension to the payroll tax holiday, only to have the House reject the deal, with Boehner saying his caucus preferred a year-long extension. Boehner gave in after the White House and Senate applied extensive public pressure.

Even if Obama chooses to disengage from Congress, there are several potential political land mines littering his playing field. Republicans successfully added a provision to the two-month payroll tax cut extension mandating that Obama make a politically sensitive decision on the Keystone XL oil sands pipeline by the end of February. He had hoped to delay a decision on the project — which Republicans have said will create jobs but environmentalists have said would harm natural resources — until after a federal environmental review is completed in 2013. Also, the Supreme Court is scheduled to rule, before the November elections, on a key provision of Obama’s health-care overhaul package, approved in 2010.

As for the election, Earnest said the president remains focused on his job as chief executive and does not intend to fully launch his campaign in the near future, while Republicans are selecting a nominee. As he travels the country and speaks to the people over the coming weeks, Obama will ask them to make their voices heard in support of his broader vision for the country, Earnest added.

“In terms of the payroll tax cut and lessons learned, certainly the president talked at the end of that debate about the importance of people all across the country speaking up and speaking out, and talking about how the decisions that were being made in Congress were having — would have and were having — a direct impact on their lives,” Earnest said. “It’s the view of the White House that that was a very forceful, persuasive addition to the debate.”