Wal-Mart -- the country's largest private employer -- is holding mandatory meetings for its store managers and department supervisors, who are being warned about the potential dangers of a Democratic win this fall, the Wall Street Journal's Ann Zimmerman and Kris Maher report.

"The Wal-Mart human-resources managers who run the meetings don't specifically tell attendees how to vote in November's election, but make it clear that voting for Democratic presidential hopeful Sen. Barack Obama would be tantamount to inviting unions in," Zimmerman and Maher write. They quote one anonymous Wal-Mart customer-service supervisor as saying:

The meeting leader said, "I am not telling you how to vote, but if the Democrats win, this bill will pass and you won't have a vote on whether you want a union." I am not a stupid person. They were telling me how to vote.

A Wal-Mart spokesman responded, "If anyone representing Wal-Mart gave the impression we were telling associates how to vote, they were wrong and acting without approval."

The law in question is the Employee Free Choice Act, which is supported by Democrats and would replace secret balloting when workers choose a union with a "card check" system, something likely to result in increased union membership.

The meetings appear to be legal, though the company may be treading on thin ice by bringing in the department supervisors. The WSJ notes, "Federal election rules permit companies to advocate for specific political candidates to its executives, stockholders and salaried managers, but not to hourly employees. While store managers are on salary, department supervisors are hourly workers." Companies are allowed to inform their workers about candidates' records and positions, however.

Wal-Mart is notorious for working to keep unions out of its stores; the WSJ recounts, "The United Food and Commercial Workers was successful in organizing only one group of Wal-Mart workers -- a small number of butchers in East Texas in early 2000. Several weeks later, the company phased out butchers in all of its stores ... When a store in Canada voted to unionize ... the company closed the store, saying it had been unprofitable for years."