02/28/2012 10:59 pm ET

Michigan Election Results: Union Members, Families Go For Rick Santorum

WASHINGTON -- Union members and their relatives who voted in Tuesday's GOP primary in Michigan broke for Rick Santorum over Mitt Romney by a wide margin, an indication that the labor community probably views the former senator from Pennsylvania as less hostile to union interests than the current frontrunner.

According to CNN exit polling, 45 percent of voters who identified themselves as union members cast their ballots for Santorum, compared with 26 percent for Romney, the former Massachusetts governor. Among voters who said someone in their household was a union member, 45 percent went for Santorum and 27 percent for Romney. As of late Tuesday night, Romney had pulled out a win in Michigan by about four percentage points.

Unlike in many other states, labor issues figured prominently in the GOP primary in Michigan, where the United Auto Workers union looms large and where residents have strong opinions about the government-financed rescue of the auto industry. According to the Bureau of Labor Statistics, more than 17 percent of the state's workers belong to unions, one of the highest rates in the country.

While in Michigan, Romney stood by the anti-labor message he's crafted throughout the primary season, and he tried to tar Santorum for what he described in Michigan as an "unapologetic defense of big labor."

In particular, Romney had recently been knocking Santorum for past votes he cast in the Senate against a national right-to-work law and in favor of the Davis-Bacon Act, the prevailing wage law supported by unions. While those sharp attacks may have hurt Romney with union-minded voters, they may have done him some favors with the larger voting public that has no union affiliations in the household. Among those voters, Romney won 44 percent to Santorum's 36, according to CNN.

Michigan union members who voted may also have been attracted to Santorum's economic plan, which stresses a robust manufacturing sector, as well as the fact that he's voiced support for private-sector unions recently.

The polling data on union members will likely stoke speculation that Santorum and unions had colluded in Michigan to tip the vote away from Romney. On Tuesday, Romney accused the Santorum camp of "teaming up" with unions to robocall Democratic voters and encourage them to vote for Santorum. Michigan is an open primary in which anyone can vote, regardless of party affiliation.

Despite the wide margin in union-member votes, Michigan voters who strongly supported for the auto bailout were generally split among the two candidates, with 41 percent of voters who approved of government support voting for Romney and 38 percent for Santorum, according to CNN's polling. Neither candidate supported the $80 billion rescue plan for America's automakers at the time, but Romney was the one who penned an op-ed in The New York Times against the idea in 2008, entitled "Let Detroit Go Bankrupt."