On the first Monday morning of June 1951, the U.S. Supreme Court issued a 22-page majority decision that, for the next six years, did the unfathomable here in the land of the free: It effectively outlawed a specific political belief. Sixty years later, that ruling stands as an object lesson in how the U.S. government should not react to stressful times by clamping down on the freedoms that define our democracy.
The case was Dennis vs. United States, and it began with a bungled investigation into Soviet spy rings. Elizabeth Bentley, an American-born spy handler who had begun to fear her Soviet masters, had turned herself in to the FBI in Manhattan and named names. The Justice Department convened a special grand jury in New York, which spent months hearing secret testimony.
Because it was a secret investigation, the newspapers naturally were filled with stories about it. Reporters and columnists wrote breathlessly about what the jurors might be hearing and speculated about how many spies had burrowed into federal agencies. Unfortunately for the Justice Department, witnesses failed to confirm Bentley's story (under oath, they either lied or took the 5th). As the grand jury investigation fizzled, Justice Department officials began looking for a way to save political face.
In the end, they decided to charge the overt leaders of the Communist Party U.S.A. with conspiring to advocate, or teach the necessity of, overthrowing the U.S. government — things explicitly outlawed under the Smith Act of 1940. Under the Smith Act, conviction did not require overt acts, just statements by the accused that they thought the U.S. government should be overthrown. Talk and belief, not deeds, were evidence of guilt.
http://www.latimes.com/news/opinion/commentary/la-oe-martelle-supreme-court-20110606,0,2491560.story