DES MOINES, Iowa » The wounds may have healed from his ferocious budget battles with the last Democratic president, but Newt Gingrich’s memory is vivid. And he believes one lesson still holds true about the fights between Congress and the White House: Presidents generally win.

It was with that sentiment in mind Wednesday that Gingrich waded — reluctantly — into the latest partisan clash in Washington that has left many Republicans worrying whether they are landing on the wrong side of a tax argument with Democrats.

"Incumbent presidents have enormous advantages," Gingrich said. "Republicans ought to do what’s right for America. They ought to do it calmly and pleasantly and happily, and over time people are smart and will figure this stuff out."

The Republican presidential candidates have built their campaigns around a sharp critique of President Barack Obama and Democrats in Congress. But their footing seemed far less certain with the contentious back-and-forth on Capitol Hill suddenly involving an internal Republican feud over the extension of a payroll tax break and jobless pay — especially at a time when Congress’ approval ratings are far below those of the president.

As he opened a three-day bus tour in New Hampshire, Mitt Romney noted that he was not willing to get into the "congressional sausage-making process." And in a round of television interviews from Iowa, Rep. Michele Bachmann of Minnesota declared, "There’s a real lack of leadership in Washington." Bachmann did not return from Iowa to Washington for the vote on the tax bill Tuesday.

The Republican field was out in full force Wednesday. The candidates scrambled trying to win over undecided voters in Iowa and New Hampshire. Yet the frenzy of activity on one of the busiest days of the campaign season so far only reinforced a seldom-spoken truth about running for president: Applying for the job often bears little reality to the actual duties of office.

With more than 3 million Americans on the cusp of losing unemployment insurance benefits because of an impasse in Congress, and all workers on the brink of losing a payroll-tax break, the presidential candidates broached the subject only when they were asked about it by reporters. And even then, they blamed Obama and Sen. Harry Reid of Nevada, the majority leader, rather than take sides in the standoff between House and Senate Republicans.

Gingrich did not seem eager to weigh in, despite his own experience of a similar budget battle in 1995 and 1996 that escalated into a government shutdown that benefited President Bill Clinton. But the subject was unavoidable as he stood before reporters here at the Iowa State Capitol, where he called a news conference to trumpet the endorsements of the House speakers from Iowa and New Hampshire.

"I’m not trying to micromanage or second-guess the Congress," Gingrich said. "I don’t pay enough attention. I’m like a normal American. I read your headline and go, ‘OK, got it,’ and go on to the next stop."

The look on Gingrich’s face seemed only slightly less pained than it was a few moments earlier when an event designed to show his strength in the two early-voting states — his campaign flew William O’Brien, the speaker of the New Hampshire House, here to Iowa — was disrupted by protesters. Gingrich had waited patiently as a handful of demonstrators shouted, "Put people first."

After they were led away, a roomful of reporters asked him whether the stalemate over extending the payroll tax break would be damaging to the Republican Party, as such influential voices like The Wall Street Journal editorial page suggested.

"In terms of the presidential election, it’s noise," Gingrich said. "It’s fairly hard for a legislative branch to outperform a president in communications."

Gingrich said that he favored a one-year extension of the payroll tax cut, as House Republicans are advocating. He assailed the Senate, whose own version of the legislation — extending the cut for two months — passed with the support of 39 Republicans, for an "absurd dereliction of duty" and "game playing."

He refrained from offering any counsel to Speaker John A. Boehner of Ohio, whose Republican caucus balked at the Senate bill. Then, Gingrich said: "I have no idea how I would try to handle it if I were in John Boehner’s position."

As he prepared to fly to New Hampshire to pick up his campaigning there, he allowed that there was plenty of blame to go around.

"I think this is an example of why people are sick of Washington and sick of politics," Gingrich said. "Obama is so inept as a president, and the Congress is so dysfunctional as an institution that we are lurching from failure to failure to failure in a way that I think the American people find very, very disheartening to think that their leadership cannot get together and be mature."

He was not alone in his reluctance to choose sides in the Republican argument.

Romney, who is locked in a tough fight for the party’s presidential nomination and is seeking to gain the support of a wide spectrum of Republicans, also did not raise the issue until he was asked by reporters as he campaigned in New Hampshire.

"As you know, I happen to support the idea of extending the payroll tax holiday," Romney said. "I don’t think this is going to change the economy, but it’s certainly going to help a lot of people in tough times. In this Obama economy, this is the last time to raise taxes. We don’t want to raise taxes at a time like this."

But he declined to say whether he supported the House Republican position to reject the two-month extension, which had the overwhelming support of Senate Republicans. Asked directly if he disagreed with Boehner, he replied: "I just told you my position. I did not say that, so I’m not going to say that I said that."

He added, "How they make that work is something they’re going to have to decide amongst themselves." With that, he turned the conversation back to a topic that he and other Republicans are eager to talk about: Obama.