WASHINGTON (CNN) -- President Barack Obama withstood a late push by Mitt Romney in Pennsylvania and also won the battleground state of New Hampshire, according to CNN projections that showed the incumbent holding key states in his blueprint for victory in Tuesday's presidential election.
While Romney held a lead in the decisive electoral count of 158-147 in the battle to reach the winning number of 270, the Obama victories in states where Romney spent major time and resources strengthened the president's position to win re-election.
Meanwhile, CNN projected that Republicans would retain their majority in the U.S. House, raising the prospect of another divided Congress with analysts expecting Democrats to hold onto their narrow control of the Senate.
New Hampshire was the first of the eight states considered up for grabs Tuesday to be projected to either candidate. All of the other races called so far went as expected after the roller-coaster ride of an election campaign that was buffeted by a superstorm and missteps on both sides.
Obama and Romney ran dead even in final polls that hinted at a result rivaling some of the closest presidential elections in history, reflecting the deep political chasm in the country.
A heavy turnout was reported in much of the nation, and both campaigns expressed confidence that they would prevail in what was expected to be a long night awaiting results from the eight states still up for grabs that will determine the victor.
As predicted, the election was set to be decided in the battleground states, with Romney increasingly needed to win most or all of them to have a chance.
However, Obama held a 51%-47% lead with almost half the unofficial returns counted in Ohio, which analysts predicted would be one of the the most vital races. No Republican has ever won the White House without capturing the Buckeye State.
In another of the key battleground states, Obama led by more than 45,000 votes in Florida with 86% of the unofficial returns counted. Romney, meanwhile, held a lead over Obama in Virginia, another vital swing state, according to the unofficial early returns. Overall, Romney held a lead of 50%-48% over Obama, or just over 1 million votes, in the national tally.
Obama will win his home state of Illinois as well as Romney' s home state of Massachusetts -- where the Republican previously served as governor. He will also win Romney's birth state of Michigan, along with New Hampshire, Pennsylvania, New Jersey, New York, Vermont, Connecticut, Delaware, Maryland, Maine, Rhode Island and the District of Columbia, according to the CNN projections.
Romney will win Kansas, Louisiana, Nebraska, North Dakota, South Dakota, Texas, Wyoming, Mississippi, Alabama, Tennessee, Arkansas, Kentucky, Indiana, West Virginia, South Carolina, Oklahoma, Utah and Georgia, CNN projects.
Voters also determined the makeup of a new Congress, choosing all 435 members of the House of Representatives and 33 of the 100 senators. Democrats and independents who caucused with them held a 53-47 advantage in the Senate heading into the election, and the unofficial returns indicated the party was likely to retain its majority.
According to early exit polls, 60% of voters said the economy was the most important issue, 59% thought abortion should be legal and 50% wanted Obama's health care reform law repealed while 43% wanted it to remain in place or be expanded.
The breakdown of voters, according to the early exit polls, was 73% white, 13% African American, 10% Latino and 3% Asian. Pre-election polls showed Romney holding an advantage among white men while Obama had the edge with white women, and Obama receiving overwhelming support among minorities.
Tuesday's outcome will influence the direction of a government and country facing chronic federal deficits and debt as well as sluggish economic growth in the wake of a devastating recession and financial industry collapse that confronted Obama when he took office as the first African-American president in January 2009.
Around the country, voters formed long lines at polling places after record numbers participated in early balloting, indicating a strong turnout.
Sporadic reports of irregularities included malfunctioning voting machines and other problems, including electoral hardships for some struggling to recover from the devastation of Superstorm Sandy in states in the country's northeast.
A judge in Philadelphia, a heavily Democratic city, ordered election officials to cover a mural of Obama at one school used as a polling location after Republicans complained the painting violated election laws.
Elsewhere in the city, GOP poll monitors were being escorted into precincts by sheriff's deputies after some observers had been denied access earlier in the day, said Tasha Jamerson, a spokeswoman for the district attorney's office.
In New Jersey, which permitted electronic balloting in the aftermath of last week's storm, the state chapter of the American Civil Liberties Union headed to court on Tuesday on behalf of voters who said their requests for an electronic ballot weren't being acknowledged.
Candidates usually take Election Day off, but both sides continued to make public appearances even as voting was under way. Obama visited a local Democratic election center in the Chicago area, while Vice President Joe Biden made "an unannounced but long-scheduled" stop in the key battleground state of Ohio.
Romney and his running mate, Rep. Paul Ryan, also arrived separately in Ohio, with Romney's campaign plane and Air Force Two, which carries the vice president, crossing paths at Cleveland's airport. Earlier Tuesday, Romney cast his ballot outside of Boston on Tuesday, while Obama previously became the first sitting president to vote early when he did so in Chicago last month.
No matter who wins the presidency, the White House and Congress will face fresh pressure to legislate a comprehensive deficit reduction deal that has been stymied so far by intransigence on the issue of tax reform, with Republicans refusing to consider any kind of tax increase while Obama and Democrats insist on at least the wealthy paying a higher income tax rate.
Despite the building drama toward Election Day in the campaign expected to cost $2.6 billion, much of the outcome already was known. Only a handful of states were considered up for grabs and both candidates and their campaigns concluded an exhausting final sprint through them over the weekend and on Monday.
The barnstorming amounted to a montage of Americana electioneering, with Obama and Romney shouting themselves hoarse before boisterous crowds, joined by top surrogates and star power such as Bruce Springsteen singing for Obama and Kid Rock for Romney.
In their final speeches, the candidates and their running mates blended inspirational visions for a better future with well-honed attacks in hopes of ensuring their committed supporters actually cast ballots while trying to coax votes from anyone still undecided.