Mitt Romney and Rick Santorum are running very closely in Michigan, according to the latest state polling, with Ron Paul and Newt Gingrich far behind. Michigan’s results will be the main act Tuesday, as most polls show Romney headed toward a comfortable victory in the Arizona primary.

Romney and Santorum score within four percentage points of one another in Michigan, according to five polls conducted over the weekend: American Research Group (Santorum +1) and automated firms PPP (D) (Romney +2), Rasmussen Reports (Romney +2), Mitchell Research/Rosetta Stone (Santorum +2) and We Ask America (Romney +4). None of these leads is statistically significant.

Roughly one in six Michigan voters has cast votes via absentee ballots, according to polls by NBC News/Marist and PPP. Romney has a roughly 2 to 1 edge among early voters in both surveys, leaving Santorum with an uphill climb when the polls open Tuesday.

Delegate math

While the Michigan race is up in the air, the delegate math is much simpler. Romney stands to win about three times as many delegates as Santorum on Tuesday, regardless of who ekes out a win in Michigan. Here’s how:

Arizona is a winner-take-all contest, and Romney’s big lead there (with the exception of American Research Group, where he is up by only four points) makes him a favorite to bank all the state’s 29 delegates, leaving other candidates empty-handed.

Michigan hands out its 30 delegates proportionally to the winner in each of its 14 congressional districts. Unless Santorum wins a surprise blowout victory in Michigan – a highly unlikely outcome – the state delegates will split about evenly. Assuming an even divide in Michigan, Romney is likely to walk away from Tuesday with about 45 delegates, compared with around 15 for Santorum.

Gingrich and Paul may wake up Wednesday with no additional delegates if they fail to win any Michigan districts outright.

(Check out the latest GOP delegate tallies with The Post’s Republican Primary Tracker).

What it means for super Tuesday

A win for Santorum in Michigan – where both candidates have campaigned fiercely on Romney’s home turf – may help Santorum pick up steam in the contests March 6 even if he fails to score a big delegate win. The sheer number of delegates at stake next Tuesday, 437, dwarfs the 59 at stake in Michigan and Arizona.

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