Free trade is quickly moving up the charts as an issue in the midterm elections. China is the biggest bogeyman this cycle, but NAFTA (North American Free Trade Agreement)—the 1993 agreement among the U.S., Mexico, and Canada that knocked down most barriers to trade—is also hitting the headlines.

Labor unions saw NAFTA, passed during Bill Clinton’s first term, as a smelly deal that would cause the U.S. to lose low-wage manufacturing jobs to Mexico. The treaty retained its stench into the 2008 presidential primaries, and both Barack Obama and Hillary Clinton promised to renegotiate its terms once they reached the Oval office. NAFTA hasn’t made the frontburner in Obama’s first two years, but in the run-up to the midterms, candidates are taking NAFTA-related shots at each other.     

As Greg Hinz reported in his blog on Crain’s Chicago Business, Mark Kirk last week denounced Alexi Giannoulias for waffling on the question of whether NAFTA should be renegotiated.

The issue could hit even closer to home because one of NAFTA’s chief handlers was Clinton White House aide—now presumed mayoral candidate—Rahm Emanuel.

In 1993, prospects for NAFTA looked so bleak that it was dubbed “Project Lazurus.” The credit for its unlikely passage went to Bill Daley, the Mayor’s brother and later Clinton’s Commerce Secretary, and Rahm Emanuel.

While writing a profile of Bill Daley in 2004,I interviewed Emanuel, who was happy to take credit for helping Daley shove the treaty through Congress. “Billy and I shared an office… [NAFTA] went from being on the respirator to a success,” Emanuel said. In a 1997 Chicago Tribune magazine profile of Emanuel titled “Mr. Fixit,” reporter William Neikirk wrote that passing NAFTA was “one of the crowning achievements of [Rahm’s] government service.” Emanuel told Neikirk that he is particularly fond of a photo he took with Clinton after NAFTA’s passage.

As Emanuel competes in the primary next February and, more likely than not, in the runoff in April, will NAFTA turn from a notch on Rahm’s big-accomplishment belt to the proverbial albatross around his neck?

In response to my e-mail requesting a short telephone interview, Emanuel’s press secretary wrote back, “It’s not possible.”

For what it’s worth, local union leaders were equally reticent.