The absolute worst song I've ever heard is William Shatner's rendition of Mr. Tambourine Man. Suddenly, there is a new contender. Barbra Streisand sings for John Kerry.

PEOPLE
I MEAN G - O - P - EOPLE -
WHO'D BELIEVE THERE'S SUCH PEOPLE IN THIS WORLD?
BUSH SEEZA
LOTTA CONDOLEEZA,
THEY'RE DIVIDING THE PLANET'S OIL
ACCORDING TO RICHARD "POIL"
AND THEY'RE ALL JUST TRAINEES
OF CHENEY'S.

RUMSFELD,
WE MUST GET RID OF RUMSFELD -
HE'S THE SPOOKIEST PERSON IN THE WORLD.
AS FOR POWELL -
HE'S NEITHER FISH NOR FOWL.
HE'S IN THE BACK OF THE ROOM,
WHILE THEY'RE ALL FIDDLING WITH DOOM.
NO ONE'S MINDING THE STORE.
WHAT'S MORE,
LET'S DISCUSS THIS WAR WE'RE LOST IN,
DON'T ASK WHAT IT'S COSTIN' -
WHAT'S A TRILLION OR TWO TO RULE THE WORLD?

It goes on and on for several more verses. And of course, there's plenty more moonbattery posted proudly on the rest of her site.

UPDATE: Fixed the Shatner link.