The recent surge of ex-senator Rick Santorum has turned tonight’s Michigan primary into one of the most eagerly-anticipated contests of the 2012 campaign. Mitt Romney has had to run hard in a state where he was once a heavy favorite; after all, he grew up in suburban Detroit, his father George was the state’s governor, and he won there easily in 2008.

Here’s what to watch for in the election results tonight in Michigan, where polls show a tight race between the pair, and Arizona, where Romney is well ahead in most surveys:

1. Did “snob” and “phony theology” work?

Rick Santorum launched a series of aggressive attacks at President Obama in the days before these two primaries, particularly through two phrases: ‘phony theology’ and ‘snob.’ Santorum, like Newt Gingrich and other Republicans in earlier stages of the race, is trying to consolidate the vote of Tea Party Republicans, who have been reluctant to support Romney, and seem to reward the most virulently anti-Obama candidate.

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The results in Michigan and Arizona will show the wisdom of this approach. Will Tea Party Republicans, particularly in Michigan, be galvanized by Santorum’s fiery rhetoric and lift him to victory? Or will Republicans who prize electability side with the more measured Romney?

2. Does Santorum have a special appeal with Catholics and white working-class voters?

Santorum argues that he would make a better opponent against President Obama than Romney in the general election because he can appeal to swing voters, particularly middle and lower-income whites and his fellow Catholics.

He was perhaps the angriest candidate in condemning President Obama when the administration began calling for all religious organizations to offer their workers coverage for contraceptives, which offended many conservative Catholics.

Michigan is traditionally a swing state, so if Santorum wins the primary on the strength of his appeal to lower-income whites and Catholics, he would have a stronger case about his electability. A loss in Michigan, and among Catholics, would weaken that argument.

3. Is Romney being permanently damaged by the primary?

Polls show Romney’s unfavorable ratings are rising, particularly among independent voters, as he faces more attacks from his rivals, the press and the Obama campaign. The results and, particularly, exit polls will show how Republican voters are now viewing Romney. Do they see him as a person they are generally satisfied with, or simply the best of a group of candidates they aren’t excited about?

4. Can Newt come back?

Newt Gingrich is looking to March 6, when 10 states hold caucuses or primaries, to revitalize his candidacy. He’s banking on surviving lackluster finishes in Arizona and Michigan. It will be interesting to see can pass Santorum in Arizona, where neither has campaigned intensely.

5. Can any of these guys beat President Obama?

In a word, maybe. The president is surging in many polls, showing his strongest ratings in some surveys since 2009. In an interview with Univision last week, he declared “I’ve got another five years” to pass immigration reform, expressing a high amount of confidence in winning re-election.

Of course, much time remains before Election Day, even though the Republican field looks lackluster right now.

Follow Perry Bacon Jr. on Twitter at @perrybaconjr