Wal-Mart, having tested the waters in Iowa, promises to step deeper into the early 2008 presidential primaries by sending "fact check" letters to its 27,000 employees in South Carolina.

The letters are in response to a cross-country campaign under way, joined by notable Democratic hopefuls, that criticizes the retail giant for its wage and benefits policies.

South Carolina, like Iowa, is one of the nation's earliest political contests for presidential hopefuls in 2008. It is set to host the first-in-the-South vote after contests in Iowa, Nevada and New Hampshire.

Wal-Mart has targeted employees in these states and says the Wake Up Wal-Mart (www.wakeupwalmart.com) campaign is a union-funded attack that seeks to distort the good the company does.

Some presidential hopefuls, including former North Carolina senator and 2004 vice presidential nominee John Edwards, have joined the Wake Up Wal-Mart tour at different stops.