DETROIT -- In this up and down Republican presidential race, Mitt Romney is up again, winning Tuesday's Arizona and Michigan primaries.
He beat Rick Santorum by three points in Michigan after a bruising campaign.
That gives Romney a big boost going into next week's Super Tuesday contests.
"We didn't win by a lot -- but we won, and that's what counts," Romney said in his victory speech.
It sounded like a big sigh of relief after Romney held off Santorum for a badly-needed victory in the state where he was born and raised. But the fact that the race was so close and so fiercely thought suggests that the Republican Party is still deeply divided about Mitt Romney.
In his speech, Romney never mentioned Santorum, and instead turned all of his fire on President Obama.
"These days," Romney said, "when he's not spending our money or infringing on our rights, he's bush running for re-election."
In Arizona Romney, as expected, won big -- beating Santorum by 20 points.
But Michigan was a nail-biter to the end.
"We came into the backyard of one of my opponents," Santorum pointed out, "In a race that everyone said, 'Well, just ignore it. You have really no chance here.' And the people of Michigan looked into the hearts of the candidates, and all I have to say is: I love you back."
Santorum made the race close by targeting blue-collar voters and keying in on social issues dear to the hearts of evangelical Christians, including birth control and religious freedom.
Now, the GOP fight moves to Washington state -- then the ten states of Super Tuesday, when more than 400 delegates are up for grabs -- 66 of them in Ohio. A new poll in that critical swing state shows Santorum with an 11 point advantage over Romney.
Despite the uncertain Republican race, the White House is keeping its focus squarely on Romney. In a speech to the United Auto Workers union Tuesday, the president praised the 2009 federal bailout of the car industry -- and took a swipe at Romney, who strongly opposed Mr. Obama's plan, saying, "The other option we had was to do nothing, and allow these companies to fail. And you will recall there were some politicians who said we should do that." The was met with boos - aimed at the "other politicians."
Romney isn't wasting any time. He heads straight for Ohio Wednesday, where he's expected to wage another tough battle with Santorum. And, if Santorum has his way, the questions and doubts about Romney will begin all over again."
To see Chip Reid's report, click on the video in the player above.