Saying “true threats” are not protected by the First Amendment, a federal judge has declined to throw out an indictment accusing a man of sending menacing messages to a slew of public figures. In a written opinion Wednesday, U.S. District Judge Virginia M. Kendall denied Ronald Haddad Jr.’s motion to dismiss 28 counts alleging he sent packages that contained written threats of violence — and, often, shotgun shells or unidentified powder or liquid — to Chicago politicians and out-of-state …