Hey, the original joke is not at all "unfunny" -- it's actually fairly witty and, if delivered effectively, should get a big laugh.

Of course, in the ORIGINAL version of the joke -- or at least the earlier version I heard (and retold repeatedly) a couple of years ago, before the Democratic party had nominated a candidate for this election -- the punchline was "..and now the sumbitch is president of the United States." GWB, in other words. The third surgeon had nothing to work with but half a human brain and a horse's ass.

Anyway, the joke should not be considered more or less offensive for substituting one politician's name for another's. Except that whoever adapted it to bash Kerry should have had the wit to work in some reference to a "horse face" -- wouldn't you think?