David Lutz, 53, of Trinity, N.C., who lives on his Army pension and flea market sales, paid tribute to Obama's resilience in explaining why he switched from supporting Clinton in the final days.
"I finally got swayed Obama's way," he said. "He's like a magician — he pulled a lot of good tricks out of his hat."
A look at the night's numbers:
Obama won at least 69 delegates and Clinton at least 63 in the two states combined, with 55 still to be divided between the two candidates.
Obama's delegate total reached 1815.5 to 1,672 for Clinton in The Associated Press count, out of 2,025 needed to win the nomination.
Obama won North Carolina 56-42, with returns from 99 percent of precincts.
Clinton won Indiana 51-49, with returns from 99 percent of precincts.
And the races still ahead:
28 delegates at stake in West Virginia in a week.
103 delegates up for grabs a week later in Kentucky and Oregon.
55 in Puerto Rico on June 1.
31 in Montana and South Dakota on June 3.
On Tuesday, Clinton fell short of the Indiana blowout and the North Carolina upset that might have jarred superdelegates into her camp in a big way.
They have continued trickling toward Obama despite the fallout over his former pastor's racially divisive remarks and Clinton's win in Pennsylvania two weeks ago.
Obama sounded increasingly focused on the fall campaign.
"This primary season may not be over, but when it is, we will have to remember who we are as Democrats ... because we all agree that at this defining moment in history — a moment when we're facing two wars, an economy in turmoil, a planet in peril — we can't afford to give John McCain the chance to serve out George Bush's third term," he said.
Clinton was joined at her rally by her husband Bill, his face sunburned after campaigning in small-town North Carolina, and their daughter, Chelsea.
The New York senator stressed the issue that came to dominate the final days of the primaries in both states, her call for a summertime suspension of the federal gasoline tax. "I think it's time to give Americans a break this summer," she said.
Obama opposes the tax suspension, calling it a gimmick.
The impact of a long-running controversy over the Illinois senator's former pastor, the Rev. Jeremiah Wright, was difficult to measure.
In North Carolina, six in 10 voters who said Wright's remarks affected their votes sided with Clinton. A somewhat larger percentage of voters who said the pastor's remarks did not matter supported Obama.
Obama and Clinton both planned to campaign in the next primary states starting Thursday, after a day in Washington. Obama headed to Chicago after his Raleigh speech before coming to the capital.