Kevin Drum of Political Animal beat me to the punch on this today, but I want to echo his suggestion that you read the New Republic's editorial on the tilting of the National Labor Relations Board during the Bush era.
Labor guys are forever talking about the need for labor law reform, and those of us who don't follow this issue regularly probably half-assume they are just worried about the general erosion of union membership, and/or want better safeguards against the kind of corporate practices (e.g., offshoring) that didn't exist when the industrial-age regime of labor laws was created in the 1930s. But as the TNR Editors show, there's a deliberate GOP effort under way to undermine those laws as they have generally been applied all along.
Organizing to collectively bargain is tough enough these days without the officials responsible for ensuring the rights of employees trying to rig the game. This is an issue on which all Democrats need to show some solidarity with the labor movement.