WASHINGTON - In a blend of pageantry and politics, Republicans took complete control of Congress for the first time in eight years on Tuesday, then ran straight into a White House veto threat against their top-priority legislation to build the Keystone XL oil pipeline.
Republicans condemned the unexpected announcement, which came at the same time they were savoring the fruits of last fall's elections and speaking brightly about bipartisan compromises in the two years ahead.
"I'm really optimistic about what we can accomplish," said Kentucky Sen. Mitch McConnell, moments after he was recognized as leader of the new Republican majority on one side of the Capitol.
At the other end of the majestic building, Rep. John Boehner of Ohio easily won a third term as House speaker despite attempts by tea party-backed dissidents to topple him. He said the 114th Congress would begin by passing legislation to "develop more North American energy" among top priorities, adding, "We invite the president to support and sign these bipartisan initiatives into law."
It was an offer the White House could and did refuse - in advance.
"If this bill passes Congress, the president wouldn't sign it," presidential press secretary Josh Earnest said before Boehner spoke. He said the measure would undermine an ongoing review process by the administration.
The events spilled out rapidly on a day that offered a glimpse of the political forces at work in an era of divided government - the intraparty struggle among House Republicans, the coordination that GOP leaders in both houses showed in pursuing a conservative agenda and the blocking power of a Democratic president.
There was well-choreographed pageantry as well on a day Republicans installed a 54-46 majority in the Senate and took 246 of the 435 seats in the House, the most in more than 60 years.
Vice President Joe Biden presided over swearing-in ceremonies in the Senate, leading new senators and re-elected veterans alike in an age-old oath to "support and defend the Constitution of the United States." He reserved his warmest greeting for former Vice President and Sen. Walter F. Mondale, 87, who accompanied Minnesota Sen. Al Franken down the chamber's carpeted center aisle to an oath-taking.
The House played host to a younger crowd as lawmakers were sworn in for two-year terms - children in their best clothes, babies in their parents' arms. "Mommy, mommy," yelled out one girl, no longer content to sit in the lap of her congressman-father.
One powerful player was absent but eager to show he would be back soon.
Democratic Sen. Harry Reid of Nevada, now the minority leader, issued a statement saying his doctors ordered him to stay away from his office so injuries suffered last week when a piece of exercise equipment broke "can continue to heal."
The statement disclosed for the first time that the 75-year-old lawmaker had suffered a concussion as well as broken facial bones and ribs.
Republicans were eager to turn to an agenda tailored to suit conservatives. They have signaled plans to write a budget that eliminates federal deficits in 10 years or less and to pass an overhaul of the tax code as well as try and reduce federal regulations they say are stifling job creation.
Hoping to smooth their path, House Republicans proposed a rules change permitting congressional scorekeepers to assume that tax cuts increase revenue to the government rather than reduce it.
That would make it easier to show a balanced budget with fewer painful spending cuts. The concept, known as "dynamic scoring," has been an article of faith among conservatives since the Reagan era three decades ago.