Romney was similarly secure in 23 states, also for 191 electoral votes.
The other nine states have seen much of the campaigning by the two men and their running mates, Ryan for Romney and Vice President Joe Biden for Obama. They were also the targets of most of the nearly $1 billion in television advertising financed by the candidates and their allies, both named and anonymous.
The nine battleground states account for 110 electoral votes combined, and include areas with particularly high joblessness (Nevada and North Carolina) as well as low unemployment (Iowa, New Hampshire and Virginia). Also large Hispanic populations (Colorado and Florida), an economy heavily dependent on the auto industry (Ohio) and the home of Romney's running mate (Wisconsin).
They reflect many of the key differences that have defined the presidential struggle. Among them are the competing visions of economic policy, the disagreement over raising taxes on upper-income Americans, the 2009 auto bailout that Obama said saved an industry and that Romney opposed, and immigration, where the Republican sought to move to the middle after calling during the primaries on illegal immigrants to self-deport.
The Senate races feature all that — and more.
Republicans must gain three for a majority if Romney wins the White House, otherwise four. There are 33 seats on the ballot, 23 currently in Democratic hands and 10 in Republican, a lopsided split that for months made the GOP favored to capture control.
But a series of unexpected turns, including Republican Sen. OIympia Snowe's retirement in Maine, Missouri Rep. Todd Akin's remark that women's bodies have a way of preventing pregnancy after "legitimate rape," and tea party-backed state Treasurer Richard Mourdock's primary victory over veteran Republican Sen. Richard Lugar in Indiana have all complicated the party's task.
Now, strategists in both parties rate Democratic Sen. Rep. Claire McCaskill the favorite for a new term in Missouri. Independent former Gov. Angus King appears to hold an advantage over major party rivals in Maine, where Democrats sought to blunt GOP attacks. Mourdock is struggling against Democratic Rep. Joe Donnelly in a race where a Libertarian candidate, Andrew Horning, appears to be draining votes from the Republican.
Even so, there are more than enough competitive races to leave the overall outcome in doubt. The closest of them, judging from the polls, are in Virginia and Wisconsin, two states where Democrats are retiring. Also in Montana, where Democratic Sen. Jon Tester is in a struggle with Rep. Dennis Rehberg, and Massachusetts, where late-campaign polls suggest Republican Sen. Scott Brown is slipping in a race with Elizabeth Warren.
Nowhere is the influence of outside groups tested more than in Ohio, where Democratic Sen. Sherrod Brown has been hit with more than $30 million in televised attack ads, designed to deliver a victory for challenger Josh Mandel.
Not even Democrats claim they will pick up the 25 seats they need to win House control, a virtual concession that the tea party-infused majority that swept to power two years ago will remain. All 435 seats are on the ballot, although only about 60 are seriously contested.
About two dozen of those involve first-termers. One freshman, Rep. Allen West of Florida, has spent more than $13 million trying to return to Congress.
Once-a-decade redistricting to take population changes into effect forced incumbents to face off in five races.
One of them gave the campaign a particularly memorable moment. That came in Los Angeles when Rep. Brad Sherman seized the shoulder of Rep. Howard Berman during a debate, yanked him toward his chest and shouted, "You want to get into this?" The two men — both Democrats — stood nose to nose before a sheriff's deputy moved between them.
"I should not have done that," Sherman said afterward. He is favored to win.
In gubernatorial races, Democratic retirements in Washington, Montana, North Carolina and New Hampshire created opportunities for Republican gains.