Mitt Romney pulled off a win in the Michigan primary tonight, though the race was close and underscored his struggles as the GOP establishment candidate seeking the party's nomination.
The former Massachusetts governor also won, by a larger margin, a contest in Arizona, a state that he was expected to take in part because of its large Mormon population.
In Michigan, Romney barely avoided the embarrassment of losing to his chief rival, Rick Santorum, in the state where he was born and where his father was a popular governor.
"We didn't win by a lot, but we won by enough, and that's all that counts," Romney said.
In 2008, Romney won the Michigan primary by nine points, over John McCain. The closeness of the vote this time around suggests that Romney won't have a huge surge of momentum at his back in the week leading up to "Super Tuesday," when an avalanche of delegates will be awarded in 10 states.
As Romney spoke to his supporters in Michigan around 10:30 p.m., he led Santorum by just three percentage points. He claimed that last week, "the pundits and the pollsters -- they were ready to count us out," referring to analyses that Santorum and Romney were running neck and neck.
Romney's victory speech was aimed squarely at President Obama, not Santorum. He mentioned the economy several times and also promised to repeal "ObamaCare," restore the country's credit rating and bring in oil from Canada that he said Obama denied by the rejection of the Keystone XL pipeline.
"He thinks he deserves a second term," Romney said of Obama. "He says, 'We can't wait.' To which I say, 'Oh, yes we can.' "
Just before 10:20 p.m. ET, ABC News projected that Romney would win in Michigan, as Santorum was speaking to his supporters. Before he took the stage, Santorum called Romney to concede the race.
"We came into the backyard of one of my opponents in a race that everyone said: 'Well, just ignore it. You have really no chance here,' " Santorum said in Michigan. "And the people of Michigan looked into the hearts of the candidates, and all I have to say is, I love you back."
Once expected to win that contest handily, Romney watched his stock fall in the state after Santorum rode a wave of popularity from his Feb. 7 victories in Colorado, Minnesota and Missouri.
After some recent comments that gave him the image of an elitist -- such as that his wife drives "a couple of Cadillacs," and that he has "great friends that are Nascar team owners" -- Romney was playing catch-up.
Santorum, meanwhile, continued to make controversial statements about social matters -- such as that he wanted to "throw up" after reading John F. Kennedy's speech on the separation of church and state, or that women fighting on the front lines might dangerously raise men's emotions -- but voters didn't punish him.
His standing deflated slightly after the last primary debate in which Romney repeatedly forced Santorum to explain his votes as a senator.
In the delegate scramble, Romney was the clear winner tonight. As the winner of the Arizona primary, he will get the state's 29 delegates while the other candidates get none. Michigan divides its delegates to candidates based on how many votes they win in congressional districts, so he and Santorum are expected to each win several.
The Democratic Party framed the results as an example of Romney taking positions to the right of the mainstream while having to drastically outspending Santorum.
"While he may have managed to win the Michigan and Arizona Republican primaries, tonight's victories have come at a great cost for Mitt Romney — he has moved far to the right in an obvious effort to pick up support from extreme Tea Party voters," Democratic National Committee Chairwoman Debbie Wasserman Schultz said in a statement while Romney spoke.
Party elders and elites had shown signs of worry that Romney was taking so long to win the primary. A top GOP senator told ABC News that if Romney didn't win in Michigan, "we need a new candidate."
Analysts have speculated on a number of popular figures in the party, including Chris Christie, Sarah Palin, Mitch Daniels and even Jeb Bush, but all of them have said they're not interested in running for president, at least this year.
As Michigan residents voted on Tuesday, Romney said in an interview on Fox News that he doesn't think the nominating process would be so contested that it leads to a brokered convention after the states have finished voting.
"That's just not going to happen," he said.
The eve of the Michigan primary, some Democrats unearthed a plan to tip the vote to Santorum by voting in Michigan's open system for the right-wing candidate, seeking to prolong Romney's journey to clinch the nomination.
With nearly every poll putting Romney and Santorum even, Democrats -- mainly a campaign consultant in Michigan and a liberal blogger -- hoped that just a few thousand votes would crown Santorum the winner. Exit polls found that one in 10 voters said they were Democrats.
According to those polls, 53 percent of the Democrats who voted in the Republican primary in Michigan picked Santorum, while 17 percent of them chose Romney.
Democrats and Santorum's campaign were calling Michigan a defeat for Romney days before the vote, based on his advantages -- chiefly that he was born and went to high school there and that his father was a popular governor.
The evening was also coupled with another loss for Republican moderates: the retirement announcement of Sen. Olympia Snowe, who said in a statement that she was quitting because she was frustrated "that an atmosphere of polarization and 'my way or the highway' ideologies has become pervasive in campaigns and in our governing institutions."