You did the right thing by calling the police/secret service. It may not be a direct threat as in a letter but that kind of display shows a level of rage and violence in the mind of this person. Violence goes in stages, that's why the secret service takes these things seriously. Where there's smoke , there is fire.
First, the hate, then the words, then the effigy, then the actual acting out violence.
Can you imagine what a riot there would be if that was an effigy of Al sharpton or Barak Obama. That would be a hate crime and so is this.
I cannot even begin to imagine that!! We live in a lopsided, crazy society now. Right is evil, WRONG is GREAT!!