WASHINGTON (AP) - Mitt Romney and Rick Santorum are trying to make the most of a mixed Super Tuesday, each claiming a measure of victory but unable to settle the most tumultuous race for the GOP presidential nomination in decades.
Romney narrowly won in pivotal Ohio, seized a home-state victory in Massachusetts, triumphed in Idaho, Vermont and Alaska, and won easily in Virginia - where neither Santorum nor Newt Gingrich was on the ballot. Romney was forced to share the attention with Santorum, who won contests in Oklahoma, Tennessee and North Dakota.
"This was a big night tonight," Santorum said. "We have won in the West, the Midwest and the South, and we're ready to win across this country."
The results padded Romney's delegate lead in the nomination fight, but they also refreshed questions about his appeal to conservatives in some of the most Republican states in the nation.
The best-funded and best-organized of the four Republican candidates, Romney vowed to press on.
"Tomorrow, we wake up and we start again," he told supporters. "And the next day, we'll do the same. And so we'll go, day by day, step by step, door by door, heart to heart."
The man they are angling to face in the general election chose the busiest day of the GOP race to speak from the presidential bully pulpit, where he dismissed the Republicans' almost constant criticism of his administration.
"Those folks don't have a lot of responsibilities," President Barack Obama said during a White House news conference earlier in the day.
"They're not commander in chief." Gingrich won his home state of Georgia, his first victory since he captured the South Carolina primary on Jan. 21.
The former House speaker said it would propel him on yet another comeback, Texas Rep. Ron Paul, still in search of his first victory of the nomination battle, had pinned his hopes on winning Idaho and Alaska but fell short in both.
Ohio was the marquee matchup, and for good reason. No Republican has won the presidency without carrying the state in the general election.
It was a second industrial-state showdown in as many weeks between Romney and Santorum and drew the most campaigning and television advertisements of the 10 Super Tuesday states.
Romney trailed much of the night but rallied near midnight. With 99 percent of the precincts reporting, he had 38 percent to Santorum's 37 percent, an uncomfortably close margin for a candidate who had spent nearly four times as much money as his rival in the state.
Romney spent $1.5 million in television advertisements and Restore Our Future, a super PAC that supports him, spent an additional $2.3 million.
Santorum and Red, White and Blue, a super PAC that supports him, countered with about $1 million combined, according to information on file with the Federal Election Commission.
There were primaries in Virginia, Vermont, Ohio, Massachusetts, Georgia, Tennessee and Oklahoma. Caucuses in North Dakota, Idaho and Alaska rounded out the contests.
In all, 419 delegates were at stake across the 10 states.
Romney picked up at least 212 delegates during the night; Santorum got 84, Gingrich 72 and Paul at least 22.
That gave the former Massachusetts governor 415, more than all his rivals combined. Santorum was second with 176 delegates, Gingrich had 105 and Paul had 47.
It takes 1,144 delegates to win the nomination at the Republican National Convention in Tampa, Fla., this summer.
In interviews across all of the primary states, Republicans said the economy was the top issue and a candidate's ability to defeat Obama was what mattered most as they cast their votes.
Ohio Republicans were sharply divided, according to the popular vote and interviews with voters as they left polling places.
Santorum triumphed over Romney among Ohioans with incomes under $100,000, while Romney won among those with six-figure incomes and up. Romney won among working women; Santorum won among women who do not work.
Santorum also was preferred by the half of the electorate that is born-again, while Romney was the favorite among those who were not.
The race moves to contests in Kansas, the U.S. Virgin Islands, Guam, Alabama, Hawaii, Mississippi and Missouri.
Voting in Puerto Rico, Illinois and Louisiana rounds out the nomination schedule for March.