In most states, at least. Some have stronger laws than others, as Catherine Fisk, a professor the University of California Irvine School of Law notes. In California, for example, the law states that "no employer shall coerce or influence or attempt to coerce or influence his employees through or by means of threat of discharge or loss of employment to adopt or follow or refrain from adopting or following any particular course or line of political action or political activity." Those laws tend to be in states with strong union presences.

Many southern states have weaker protections, including Florida, where Siegel and ASG are located. Essentially, it comes down the employer's right to free speech, says Joseph Little, a professor emeritus at the University of Florida School of Law. "The traditional notion of employment in Florida is referred to as employment at will. That means that the employers can discharge an employee at any time for any reason, which could include a political reason," he said. But he also said the way the letters are phrased could be relevant. Each of the examples uncovered so far involves cajoling: If Obama wins, we think he'll raise taxes and tank the economy; if that happens, we might have to lay you off, and therefore we strongly recommend you vote Romney. "If they said, 'If Mr. Obama gets elected I'm going to fire y'all no matter what happens to the business, then that is a threat," Little says. "Even so, if it's employment at will, most likely there's nothing illegal about that. That's brutal, it's hard politics, but that's the nature of employment of will."

Things could be stickier in Oregon; Elk got materials sent to Georgia Pacific employees there. The Beaver State has a law against political communications to "captive audiences," so a manager couldn't call a mandatory meeting and talk politics, but the law is mostly untested, and it's not clear that it would cover written communications anyway. But another law might. It prohibits use of "undue influence" -- defined as including " loss of employment or other loss or the threat of it" -- to convince someone to vote in any particular way. Koch Industries told In These Times it was simply offering information, and noted that unions often distribute sample ballots too. But of course the relationship between an individual and his collective bargaining unit is entirely different from his relationship with someone who can fire him -- and is actively suggesting that might happen. It's arguable that the Georgia Pacific materials violated this law, says Henry Drummonds, a professor at Lewis and Clark Law School in Portland.

Unsurprisingly, the AFL-CIO takes a more expansive view of the protections afforded to workers. Associate general counsel Laurence E. Gold suggested that the employers could be breaking either criminal or civil law, though both are ambiguous in this situation. But Gold and others see a connection between rules in the National Labor Relations Act and political activism. Employers are barred from, for example, threatening to close a plant if employees unionize. By analogy, lawyers see a way in which threatening to close a plant if workers fail to elect the right candidate might also be barred, although it isn't clear that courts would find the same.