In the last couple days, some highly reputable sources have been highlighting the union movement’s disillusionment with Barack Obama. New York Times labor journalist Steven Greenhouse (one of the few remaining in the field) reported on the issue in today’s paper, emphasizing the negative affect an alienated labor movement could have on Democratic chances in the 2010 elections.

Because unions have been so crucial to the Democrats election after election, political experts say labor’s ambivalence, or worse, toward the Democrats could greatly deepen that party’s woes this fall.

Unions aren't going to abandon their only political allies. It just isn't going to happen, at least on the executive level. Where else could unions turn? They certainly aren’t going to start supporting Republicans (PATCO tried that in 1980, and look how they ended up: dead) and doing nothing would amount to the same thing.

No matter how disillusioned and cantankerous labor leaders become, they will still throw their endorsements and their money behind Democrats. Consider the 1994 midterms, two years after the election of Bill Clinton. Labor backed Clinton in 1992, pumping tens of millions of dollars into his campaign. They particularly liked his stance against the North American Free Trade Agreement (NAFTA), a piece of legislation that industrial unions feared would result in the outsourcing of high-wage manufacturing jobs. But after Clinton was elected he changed his tune, throwing all of his muscle behind passing NAFTA. Labor leaders were appalled and threatened to slow, even end, their support for Democrats in the next elections if the bill passed, which it did in 1994.

Did union political action funds drop off as a result of Clinton’s betrayal? Barely. Labor’s monetary support of Democrats in 1994 dropped to $48.9 million, a mere $700,000 less than in the 1992 election. In 1996, when Clinton was up for reelection, union support for Democrats shot up to $60.6 million.

If NAFTA, which arguably lost almost 1 million high-paid working class jobs, didn’t completely sour labor on the Democrats, nothing will. But as Greenhouse points out, the real Dems bigger problem may be the membership (in 2008 Obama beat McCain by 18 points among white male union members, the numbers were almost exactly reversed for white, male nonunion members). That’s the real question: will labor still be able to get the rank-and-file to the polls?

Correction: I incorrectly stated that Clinton opposed NAFTA in the 1992 primaries. Actually, Clinton said he would support the treaty, but he played to labor and the environmentalists by saying he would only support it if provisions were included to protect U.S. jobs, Mexican workers and the environment. He didn't follow through. For more details see comment 8.