With a few counts still incomplete, the Republicans were certain of 52 of the 100 seats in the Senate against 44 for Democrats. They had secured 243 seats in the House to just 178 seats for the Democrats.
If voters were voicing frustration with gridlock in Washington, it was unclear if the new divided landscape would help. Both Obama and the Republicans, who will choose the current Minority Leader, Mitch McConnell, to replace Harry Reid as the new Senate Majority Leader, must decide whether to try to work together in a spirit of compromise or return to familiar patterns of combat and confrontation.
Republicans, believing they have a strong mandate, will be impatient to embark on a legislative agenda to their own liking. Areas where co-operation between Congress and the White House may be conceivable include tax reform and negotiation of overseas trade treaties.
In a sign of conflict to come, McConnell was already signalling that his party would react to punish Obama if he attempts, without consulting Congress, to enact changes in America's immigration policy by executive order to aid undocumented families as he has promised. He also termed the healthcare reforms a "huge mistake" and hinted he would seek to amend some of the key provisions.
But he insisted that divided government in Washington need not spell gridlock. "We ought to start with the view that maybe there are some things we can agree on and make progress for America."
Senator Mark Warner of Virginia was bracing himself for a possible recount as tallies showed him beating challenger Ed Gillespie, a prominent Republican consultant, by only a few thousand votes. Almost no one had considered Warner vulnerable.
New Jersey Governor Chris Christie, as chairman of the Republican Governors' Association, was able to take some of the credit for the gains. That in turn could help resurrect his hopes of becoming a frontrunner in the Republican presidential nomination derby in 2016. Christie urged Obama and his colleagues in Congress to end the deadlock in Washington.
How the picture has changed for the presumed Democrat frontrunner in 2016, Hillary Clinton, is murky. The recolouring of so many states from blue back to red suggests her climb would be tougher. Yet no new Democrat stars emerged from Wednesday and the Republicans risk a backlash against them two years hence if their stewardship of the Congress results in more, not less, dysfunction.