Primary: State-by-State Results

ALABAMA

Democrats — Sen. Barack Obama won the southern state, holding back the efforts of Sen. Hillary Clinton through much of the region. The African-American vote figuring in as a heavy, but not the only, factor in his support. Across Alabama, about half of the Democratic voters were black, and Obama, the Illinois Senator, won 80% of their votes. Exit polling also showed he captured 60% of the votes from people under 30, who made up more than one in 10 voters.

Republicans — Mike Huckabee won votes from the state's evangelical voters, who appreciated his background as a Baptist minister and viewed him as the most conservative candidate, according to exit polls.

ALASKA

Democrats — Barack Obama added the northernmost state to his list of wins, although voter turnout was low.

Republicans — Mitt Romney enjoyed a decisive victory Tuesday, capturing some 45% of the vote. Far behind in second place was Mike Huckabee, with just over 20%. Reports indicated that Alaskans fought sizeable crowds and bone-chilling weather Tuesday to cast their votes in the day's caucuses.

ARKANSAS

Democrats — Hillary Clinton won the state where she had been First Lady for several years before entering the White House with her husband, Bill Clinton.

Republicans — Mike Huckabee also took the state where he had served as governor until early last year. Here, he also enjoyed widespread support among the state's evangelical voters.

ARIZONA

Democrats — Hillary Clinton won the state, leading among those who said experience was the most important trait for candidates.

Republicans — John McCain won his home state's G.O.P. primary Tuesday, beating out Mitt Romney and Mike Huckabee, and in the process overcoming anger from conservatives who oppose his stance on illegal immigration. Throughout the campaign, conservatives hammered McCain for his support of a path to citizenship for illegal immigrants — a touchy issue here, where more people cross illegally than any other state along the U.S.-Mexico border.

CALIFORNIA

Democrats — Hillary Clinton took the big prize in California, worth the most delegates of all the states. The win, most likely bolstered by votes from women and Hispanic voters, guards against the momentum of Barack Obama's aggressive showing on Super Tuesday. The crucial win, however, does not mean that she has taken a decisive advantage in the campaign.

Republicans — Claiming a needed victory from Mitt Romney, McCain took the California primary and emerged as the clear front-runner among Republican candidates. With command of the G.O.P. nomination in his favor, it falls upon his opponents to find a way to arrive at the Republican convention with enough delegates.