The cold war between Wal-Mart Stores Inc. (NYSE: WMT) and the unions is heating up again.

Earlier this month, the Wall Street Journal reported that the world's largest retailer had warned employees that a Democratic president would back the Employee Free Choice Act, a law that would make it easier for unions to organize workers, which the company opposes. The paper now is saying that the union groups have asked the Federal Election Commission to investigate the matter, which they claim violates federal law.

Of course, this is a brilliant public relations move by the unions. First of all, the FEC is as toothless as some Wal-Mart greeters. Even if the FEC finds that Wal-Mart broke the law, the worst that the company will get is a slap -- make that a tickle -- on the wrist. That may not even happen until well into an Obama administration, which brings up my next point.

Why is Wal-Mart set to pick a fight with the Democrats? Don't the folks in Bentonville read the political tea leaves? Odds are pretty good that the country will go Blue in a big way. Maybe the company is worried that the good times reflected in today's results won't last.