Threatening the President of the United States is a class E felony under United States Code Title 18, Section 871. It consists of knowingly and willfully mailing or otherwise making "any threat to take the life of, to kidnap, or to inflict bodily harm upon the President of the United States".
As we march towards justice equality for ALL, it would be against united states federal law to refrain from pressing charges against Joe Walsh. He declared war and immediately told the president to "watch his back" a clear threat against the safety of our president!