Yesterday, the San Diego city council voted to ban certain kinds of large retail stores from the city limits. The council did not explicitly mention Wal-Mart Stores, Inc. (NYSE:WMT), but the definition of the stores to be prohibited makes it pretty clear that they had the giant retailer in mind.

Specifically, the nation's eight largest city voted to ban stores that are larger than 90,000 square feet and that use at least 10 percent of their floor space to sell groceries, which are not taxed in California. Apparently, only Wal-Mart Supercenters meet this criteria. Wal-Mart Supercenters are on average 185,000 square feet and offer groceries along with the usual Wal-Mart products.

Jerry Sanders, the mayor of San Diego, has threatened to veto the measure. He claims that city council is engaging in "social engineering." Supporters of the measure made the usual points: Wal-Mart drives local shops out of business, provides low wages, and creates traffic problems and pollution around its giant stores.

The struggle between Wal-mart and its critics has been going on for years now. Chicago city council recently voted for a living wage measure that was aimed largely at Wal-Mart and would have forced the company to pay higher wages to its workers in the city. However, the mayor of Chicago overrode city council's vote. Will the same thing happen in San Diego? Are these mayors simply corporate stooges, willing to do whatever it takes to allow Wal-Mart to make lots of money in their cities? Or are they looking out for their citizens' best interests, trying to attract retail jobs and fight high unemployment, no matter what the wages? Maybe it's a little bit of both.