Reply #149: Yates vs. United States even says Limbaugh is protected. Link included.

[Fire_Medic_Dave]

Yates v. United States

The Supreme Court of the United States said that for the Smith Act to be violated, people must be encouraged to do something, rather than merely to believe in something. The Court drew a distinction between a statement of an idea and the advocacy that a certain action be taken. The Court ruled that the Smith Act did not prohibit “advocacy of forcible overthrow of the government as an abstract doctrine.” In Justice Black's opinion, he wrote of the original Smith Act trials:
"The testimony of witnesses is comparatively insignificant. Guilt or innocence may turn on what Marx or Engels or someone else wrote or advocated as much as a hundred years or more ago.<...> When the propriety of obnoxious or unfamiliar views about government is in reality made the crucial issue, <...> prejudice makes conviction inevitable except in the rarest circumstances."
The convictions of the indicted members were reversed.

http://en.wikipedia.org/wiki/Yates_v._United_States