WASHINGTON — Taking formal control of the House, Republicans returned to power triumphant from the midterm election but still facing doubts and tensions about their role in a country with an uncertain economy, massive budget problems and a deeply split electorate.
New House Speaker John A. Boehner (R-Ohio), taking his place Wednesday as one of the country's most powerful men, immediately confronted turmoil within his own ranks between activist conservatives with a distrust of federal power and mainstream Republican leaders demanding the party face the country's problems as "grown-ups."
Boehner strived for a bipartisan tone to mark the first day, mildly choking up, as he has done during other milestone moments. He acknowledged that the second chance his party had been given was tenuous.
"The American people have humbled us," Boehner said. "They have refreshed our memories as to just how temporary the privilege to serve is."
Still, the new House leader was hard-pressed to subdue calls from the GOP faithful for swift and extreme action against President Obama's agenda, beginning with the law passed last year restructuring the nation's health insurance system.
The 112th Congress convened as an unlikely Republican renaissance just two years after Obama was swept into office, and the GOP replaced Democratic dominance with divided control of Washington.
Of 94 new members of the House, 85 are Republican, many of them self-described citizen legislators relying more on their passion for small government than any prior experience in elected office.
Vice President Joe Biden swore in 13 new senators, including 12 Republicans. Special tribute was paid to Sen. Barbara A. Mikulski (D-Md.) for becoming the longest-serving female senator in history, surpassing Sen. Margaret Chase Smith (R-Maine), who served four terms until her defeat in 1972.
Amid the celebrations, the difficulties facing Republicans were apparent in widely conflicting predictions of how much money could be cut from the federal budget. While House GOP leaders were scaling back their estimates, other party members were expanding theirs.
Their dilemma fueled questions as to which Republican Party was returning to power: the establishment wing that served under President George W. Bush, or the "tea party"-backed newcomers who are more demanding.
On the first day, however, differences were largely set aside in deference to Republicans' exhilaration over the chance to wield more influence over the nation's affairs.
As Boehner strode down the center aisle of the House chamber, his colleagues erupted in cheers as he ascended the dais to accept the gavel from outgoing Speaker Nancy Pelosi (D-San Francisco).
Boehner dabbed his eyes with a handkerchief as Pelosi waved to the new speaker's wife, Debbie, who was watching from the visitors gallery. Ten of Boehner's 11 siblings watched as the son of an Ohio tavern owner took the job he had sought for two decades.
Boehner won Wednesday's formal speaker's election on a 241-173 vote. Nineteen Democrats did not vote to retain Pelosi as speaker, reflecting the strain over her leadership resulting from the party's loss in November.
Pelosi, the first female speaker of the House, relinquished the gavel only after reciting the legislative accomplishments under the Democratic Congress, including key provisions of the healthcare law detested by Republicans.
Many lawmakers on the GOP side of the chamber grumbled as she spoke, and Boehner acknowledged the deep political divisions. "A great deal of scar tissue has built up on both sides of the aisle," he said.
Yet, as Boehner spoke and as Sen. Mitch McConnell of Kentucky, the Republican leader, watched, the challenges posed by their expanded ranks had already begun to show.
The Republicans' plan to attack the healthcare bill as their first order of business has drawn scrutiny amid the country's struggling economy.
House GOP officials acknowledged that they would have to scale back plans to cut non-Defense discretionary spending by $100 billion during their first year in power, even as conservative new Sen. Rand Paul (R-Ky.) suggested that as much as $500 billion in cuts could be achieved.
Spending cuts had been a centerpiece of GOP campaign efforts and a signature plank of the party's "Pledge to America."
Republicans explained that because the outgoing Democratic Congress had approved spending that funds the government over the first six months of the 2011 fiscal year, through March, Republicans now will have only six months remaining in which to impose cuts.
"The thing is, if we cannot hit that $100-billion goal, we have to be able to articulate why we couldn't," said tea-party-backed freshman Rep. Allen West (R-Fla.). "Where do fall short, we have to be able to explain that."
Rep. Paul D. Ryan (R-Wis.), the incoming chairman of the House Budget Committee, insisted the $100-billion pledge would still be met by year's end.
"If you think we're stopping shy of $100 billion in cuts, you've got another thing coming," he said.
Republicans acknowledged the divisions within their ranks but suggested a mandate from voters would guide them in the coming two years.
"The clarity with which the country spoke in November just took away any ambiguity about what we need to do," said Rep. Peter Roskam (R-Ill.).
But on Wednesday, as Republicans returned from a political wilderness many had expected to wander for years longer, that seemed an agenda item for another day.
Times staff writer Richard Simon in Washington contributed to this report.