CNN) -- CNN projects that Barack Obama will be the nation's 44th president.
CNN projects that Sen. Barack Obama will win the presidential election.
1 of 3 more photos » As polls closed on the West coast, the Illinois senator was projected to receive enough electoral votes to pass the 270-vote threshold.
Obama is projected to win California, Washington, Oregon and Hawaii.
He also is projected to win Virginia, a state that hasn't voted for a Democratic president since 1964.
As Obama built up a commanding lead over Sen. John McCain, senior aides to the Arizona senator were growing pessimistic about his chances.
When asked if they saw a path to victory, two senior McCain aides said no.
CNN earlier projected that Obama will win Ohio, a key battleground state with 20 electoral votes. Watch more on Obama's Ohio win »
No Republican has won the White House without winning Ohio. Going into the election, polls showed Obama with a 3-point lead there.
Obama and McCain are running a tight race in Indiana as results are tallied in the battleground state.
With about 85 percent of precincts reporting, McCain held a slim lead in the state.
In addition to the presidential contest, voters were making choices in a number of key House and Senate races that could determine whether the Democrats strengthen their hold on Congress.
Former Gov. Mark Warner, a Democrat, will win a Senate seat in Virginia, CNN projects. He will replace retiring Republican Sen. John Warner.
Incumbent Sen. Elizabeth Dole, a Republican, is projected to lose her North Carolina seat to Democratic challenger Kay Hagan. Watch Dole concede defeat »
Dole is the wife of 1996 Republican presidential candidate Bob Dole.
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CNN also projects Democrats will win two other Senate seats currently held by Republicans. In New Hampshire, former Gov. Jeanne Shaheen will win over incumbent John Sununu, and in New Mexico, Democrat Tom Udall will defeat Republican Steve Pearce.
Senate Minority Leader Mitch McConnell held onto his seat in Kentucky.
Delaware voters re-elected Obama's running mate, Sen. Joe Biden, to his seventh term. iReport.com: Share your Election Day reaction with CNN
CNN's Ed Henry said there were lots of long faces in the lobby of the McCain headquarters at the Arizona Biltmore hotel as McCain allies watched returns showing Senate Republicans losing their seats.
McCain and Obama were both expected to be watching the results come in from their home states.
McCain said Tuesday night that he was "looking forward to the election results." Watch what McCain says about the race »
"We had a great ride. We had a great experience. It's full of memories that we will always treasure," he said aboard his election plane.
CNN does not project a winner in any state until all polls have closed in that state.
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CNN projections are based on actual results and exit poll data from key areas.
The first exit polls out Tuesday reflect what voters have said all along: The economy is by far the top issue on their minds. Watch more on the top issues »
Sixty-two percent of voters said the economy was the most important issue. Iraq was the most important for 10 percent, and terrorism and health care were each the top issue for 9 percent of voters.
The economy has dominated the last leg of the campaign trail as Obama and McCain have tried to convince voters that they are the best candidate to handle the financial crisis.
Voters expressed excitement and pride in their country after casting their ballots Tuesday in what has proved to be a historic election.
When the ballots are counted, the United States will have elected either its first African-American president or its oldest first-term president and first female vice president.
Poll workers reported high turnout across many parts of the country, and some voters waited hours to cast their ballots.
Reports of minor problems and delays in opening polls began surfacing early Tuesday, shortly after polls opened on the East Coast.
CNN is asking people to call its Voter Hotline at 1-877-GO-CNN-08 (1-877-462-6608) if they witness any problems or irregularities. Read about election problems
The presidential candidates both voted early in the day before heading out to the campaign trail one last time. Watch Obama family at polls »
Tuesday also marked the end of the longest presidential campaign season in U.S. history -- 21 months -- and both candidates took the opportunity to make their final pitch to voters.
As McCain and Obama emerged from their parties' conventions, the race was essentially a toss-up, with McCain campaigning on his experience and Obama on the promise of change. But the race was altered by the financial crisis that hit Wall Street in September. Watch how this election is history in the making »
Obama began to pull away in the polls nationally as well as in key battleground states. A CNN poll of polls calculated Tuesday showed Obama leading McCain 52 percent to 44 percent, with 4 percent undecided.
Although most of the attention has been focused on the presidential race, the outcome of congressional elections across the country will determine whether the Democrats increase their clout on Capitol Hill.
Few predict that the Democrats are in danger of losing their control of either the House or the Senate, but all eyes will be on nearly a dozen close Senate races that are key to whether the Democrats get 60 seats in the Senate.
With 60 votes, Democrats could end any Republican filibusters or other legislative moves to block legislation.
Many political observers also predict that the Democrats could expand their majority in the House.
Voters will also weigh in on a number of ballot initiatives across the country, many of them focused on social issues like abortion and affirmative action. Check out the hot-button issues on the ballot