>I can’t locate a complete copy of the poem, which seems to have disappeared down the Ministry of Truth’s memory hole, <
It is in the complaint:
http://www.wlky.com/download/2010/0219/22615404.pdf
It is also here but be forewarned about clicking on it if you are at work.
http://whitereference.blogspot.com/2010/02/johnny-logan-spencer-latest-thought.html
There is nothing in the poem that indicates that the target of the sniper is the President and there is nothing in the poem which actually threatens anyone.
It is obvious that the only reason he was prosecuted was because of where the poem was posted and not because of the content of the poem itself.
The poem is filled with racist references, but then so is nearly every single rap song ever published.