The former Massachusetts governor made a play for tea party support, too, at a pair of appearances, but for the most part campaigned on his pledge to use his background as a successful businessman to help create jobs and fix the economy. Last week, he issued a call for 20 percent across-the-board cuts in personal income tax rates.
But he was hampered by off-the-cuff comments that reinforced his difficulty in reaching out to struggling voters in a state with 9.3 percent unemployment. He said at one point that his wife drives a couple of Cadillacs, and at another that he was friends with some of the owners of NASCAR teams.
At a rare news conference after the polls opened on Tuesday, he conceded that his own mistakes had hurt his campaign.
The primaries in Michigan and Arizona were the first contests since Romney squeaked out a victory over Paul in the Maine caucuses on Feb. 11, a lull of two and a half weeks.
Except for a debate in Arizona last Wednesday and a brief burst of campaigning in the hours before and after, Romney and Santorum have focused their time and campaign money on Michigan.
Polls showed Santorum racing to a large advantage after his victories on Feb. 7, before the weight of attack ads by a Romney-aligned super PAC and the candidate himself began to narrow and finally erase the gap in many surveys.
In the end, the combination of Romney and the outside group accounted for about $3.8 million in TV ads, compared to about $2.2 million for Santorum and a super PAC supporting him.
While that gave Romney an advantage, it wasn't nearly as lopsided as in some of the earlier states.
Kasie Hunt reported from Michigan
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