Dont FORCE your self to write... seriously that's the quickest way to get writers block... just be imaginative, and remember it doesn't HAVE to make sense, and most of all, dont force rymes, it sounds strained and cheesy...
Off the top of my head (kinda like free style rap)... so, here it goes sukkas;

convulsive conservatives say
"an man with open mind
is a man with an empty head"
right wing radicals,
singing my obituary,
in a key not hither to
known to the poeple of these parts,
Still, a happy man is just a
happy man.
I cant fill the landfill,
but it's becoming a gaint
elephant trap.
Landslide elections,
mudslides in south america,
decomocrats selling conglomorates,
republicans selling ashes,
a raving tramp, lays wasted.

ps: the "a man with an open mind is a man with an empty head", is a real quote from a right winger. What was funny was the guy was quite clever, cos he set up some clever arguments, just sadly he was narrow minded on some topics. But to be fair he was for a an america where regardless of you race, you could be treated as an equal provided you didn't act against the intrests of the country or it's citizens and taken some initaitive to learn about the constitution. so that was kinda good.
but yeah, nonsense is good (much less restrictive)... cos some times you stop meanings you hadn't intended, and you could change it into something more sensible..