Even in the most conservative areas, Romney's organization has brought in major donors. Romney has raised $1.62 million in Michigan to Santorum's $42,365, according to data released last week by the Federal Election Commission.
Santorum doesn't have campaign offices in any of the state's congressional districts where supporters can get information or help out with phone banks. A lot of Santorum backers instead are reaching out through their email and social media networks to spread the word about him, Clark said.
Romney can draw some comfort from Michigan's 2008 GOP presidential contest, which he won by 9 percentage points. Polls showed Romney and Arizona Sen. John McCain locked in a close contest, but Romney's strong organization prevailed against a much weaker McCain operation.
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