If there are indeed no laws on the books that have currently been broken, any attempt by the Congress to pass a law criminalizing (and punishing) behavior that was legal in the past would be a direct violation of Article I, Section 9, Paragraph 3 of the U.S. Constitution:
No bill of attainder or ex post facto Law shall be passed.
The Constitution, you say! No one hates it more than socialists. It is in writing, the supreme law of the land. Commies have been trying to destroy it for about 150 years one way or another. The most effective means is the United States Supreme Court. Ask FDR who needed it to verify his particular brand of socialism. When The Court would not, he tried to add a few more commies to the US Supreme Court.
yitbos