Due to our First Amendment to our Constitution (in the Bill of Rights), freedom of the press makes it very hard to sue the press for libel.
The main item that has to be proved is not that they got their "facts" wrong concerning a public figure, but that they deliberately told a lie from MALICE.
Without malice, there is no case. However, suits have been won against the press.
Newsweek might need to worry more about civil suits rather than any criminal charges