There were no knockout blows, but Sen. John McCain of Arizona emerged from Super Tuesday's balloting as the indisputable front-runner for the GOP nomination, while Democrats split their support between Sen. Hillary Clinton of New York and Sen. Barack Obama of Illinois.
McCain's main rival, former Massachusetts Gov. Mitt Romney, trailed by a wide margin, winning fewer states and fewer delegates, as did former Arkansas Gov. Mike Huckabee.
Clinton, meanwhile, won in California, the biggest prize of the evening. She took all but one of the large states — Illinois. But her battle with Obama for the nomination is far from over.
Latino voters showed up in force for Clinton in California, while Obama's strength among African Americans allowed him to post decisive victories in the South.
Obama won 13 Super Tuesday states; Clinton won eight, plus American Samoa.
By winning bigger states, Clinton took a narrow lead in the overall delegate count. But the road ahead remains long for the Democrats: It takes 2,025 delegates to claim the nomination and Clinton is barely a third of the way to that total, with Obama in striking distance.
Speaking in Chicago, Obama told a noisy election-night rally, "Our time has come. Our movement is real. And change is coming to America."
Clinton told supporters that she looked forward "to continuing our campaign and our debate about how to leave this country better off for the next generation."
McCain won in California, New York, New Jersey, Connecticut, Missouri, Delaware and his home state of Arizona — each of them winner-take-all primaries. He also picked up Oklahoma and Illinois.
Huckabee won a series of Bible Belt victories: in Alabama, Georgia and Tennessee, as well as his own home state. He also triumphed at the Republican West Virginia convention. Romney won a home-state victory in Massachusetts. He also took Utah, where fellow Mormons supported his candidacy, as well as North Dakota, Montana, Minnesota, Alaska and Colorado.
"We've won some of the biggest states in the country," McCain told cheering supporters at a rally in Phoenix, hours before he was proclaimed the winner in California. An underdog for months, he proclaimed himself the front-runner at last, adding, "I don't really mind it one bit."
In the past two months, the Democratic presidential field narrowed from a crowd of contenders to two main front-runners. John Edwards, the former senator from North Carolina and 2004 vice-presidential nominee, was the most recent candidate to drop out of the race, having failed to score a win in any of the early contests.
McCain was the GOP candidate with the most momentum going into Super Tuesday. He owes his victory in states such as New Jersey and Connecticut, in part, to the endorsement of Rudolph Giuliani, the former New York mayor who dropped out of the race after seven consecutive losses.
McCain's biggest challenge remains winning over conservative voters. Many are suspicious of the Arizona native's past efforts to back a path to citizenship for illegal immigrants.
Huckabee, who calls himself the "real conservative" in the race, said Tuesday that he's not about to drop out, even though he is trailing McCain by a wide margin in the delegate race.
"The one way you can't win a race is to quit it, and until somebody beats me, I'm going to answer the bell for every round of this fight," he said.