In the run-up to the Michigan primary, Mitt Romney has been on an anti-union tear. Partly this has consisted of broad (and curiously anachronistic) castigations of “stooges” and “bosses.” But Romney has also trained his anti-labor ire on Rick Santorum, the current frontrunner in the state primary. On Wednesday, his campaign released a fact-sheet titled “Big Labor’s Favorite Senator” seeking to blunt Santorum’s self-proclaimed appeal to working class voters.

But if Santorum is Big Labor’s favorite anything, Big Labor has a strange way of showing it. When I reached out to a number of prominent union leaders from Santorum’s home state of Pennsylvania, they didn’t have many warm recollections about him to share. Aside from a few token votes, they maintained, Santorum was as right-wing as the next Republican.

ROMNEY’S CURRENT LINE of criticism against Santorum, as detailed in the press release, focuses on four pro-labor stances Santorum took in the 1990s, including his “no” vote on a national Right-to-Work law, and his refusal to support repeal of the Davis-Bacon Act, which mandates paying workers prevailing union wages on public works projects. Among other liberal heresies, Santorum also voted against NAFTA in 1993 and backed steel tariffs on foreign imports. Such betrayals have rankled more than a few prominent conservatives: A day before Romney’s mailer, The Washington Post’s Jennifer Rubin practically exhorted him to attack Santorum’s “very pro-labor” record.

But Pennsylvania labor unions hold Santorum in no better esteem than do hard-line libertarians. Jack Shea, the head of the Allegheny County Labor Council, said, “I can’t remember him being an ally to labor ever,” adding, “Just by voting against the minimum wage twelve times—it was seared in our minds.” The minimum wage issue is emblematic of Santorum’s relationship with labor. In 2005, he co-sponsored a piece of doomed legislation to raise the minimum wage on the same day he voted against a different, more realistic bill that would have done the same thing. In other words, a few token votes, set to the backdrop of a hostile agenda, did nothing to appease the unions.

Put another way: Santorum’s occasional pro-labor stances were the products of political expediency. Rick Bloomingdale, the president of the Pennsylvania AFL-CIO, told me Santorum “will go whatever way the wind blows.” Bill Ehman, a local steelworkers union chief agreed: “I’ll be honest with you. He was pretty much like he is now. A political whore.” The Latrobe-based Ehman, whose chapter is near Santorum’s old congressional district, added that when Santorum did vote with unions’ interests, as with the 1996 right-to-work bill, it was because he knew it wouldn’t make a difference. (The bill failed 68-31.)