A new record for turnout was expected after voters across the state waited for hours to cast ballots, in the end bypassing Obama's mantra of change in favor of the Arizona senator's experience and support for the war in Iraq.
"I think in case of crisis he certainly would be able to handle the situation," said Wilbur Burbage, 69, of Mount Pleasant.
The Associated Press called the race shortly after polls closed. The call was based on an analysis of voter interviews, conducted for The Associated Press by Edison Media Research and Mitofsky International.
Besides the presidential election, voters also sent Republican U.S. Sen. Lindsey Graham back to Washington for a second term. All six congressional posts, every seat in the state Legislature and three proposed amendments to the state constitution also were being decided.
McCain's win was a vindication of sorts. His 2000 primary bid stalled in South Carolina and he ultimately lost to George W. Bush. But his victory in a hard-fought January primary put wind behind his campaign.
Perhaps the only thing that appeared to bother South Carolina voters on Tuesday was his choice of Alaska Gov. Sarah Palin for vice president.
"I feel he has the best eye on foreign policy. I feel more comfortable with him," said Margaret Shackelford, a 58-year-old middle school math teacher who lives in Columbia. "It bothers me she's so inexperienced. It's like the Republican Party plucked her out of nowhere."
Nearly every black voter cast a vote for Obama and about three-quarters of all white voters opted for McCain, according to the voter interviews.
"We need change in this country and that's the way to go," said Joan Price, a 47-year-old black marketing specialist who voted in Columbia.
Voter registrations were up this year, in part due to the furious campaigning leading up to the presidential primaries back in January. Since the primaries, with the state considered a lock for the Republicans, Obama has not returned and McCain came back only once for a fundraiser.
Still, the Obama campaign kept an organization in the state. Officials say a record 2.5 million people registered and, in recent months, blacks signed up to vote at nearly twice the rate of whites.
In Greenville, 105-year-old Annie Mae Rosemond cast her vote for Obama.
Assisted by her two-great-grandsons and her granddaughter, Rosemond, who is black, arrived in a wheelchair at the YWCA at around 10 a.m. and passed others waiting in line after she removed an Obama button.
"I felt he would make a good president," said Rosemond, who received a round of applause from a long line of voters as she left.
While some poll managers said the turnout was massive, state elections officials said there were few serious problems at the polls - mostly people unable to find their proper polling places. Around the state, people waited for hours, many waiting in lines before dawn.
For some, the long lines were too much. The Rev. William Roof left an elementary school polling place in Columbia without voting because the wait was about 2 1/2 hours.
"Nothing's going to change. I don't care if it's a Republican or a Democrat, they're not going to do anything to solve health care, the economy and the environment," said Roof, 53, a Columbia resident who serves as a minister at a nondenominational church.