OK, it's sad that enough people are passing this around as if it's real that it would make it to snopes.com, but this is really funny. The 50% figure shows that they're just talking about the half of American society that is below average, but what the genius of it is the totally over-the-top statements the various politicians say about people who are merely below average ("do not possess the competence and drive necessary to carve out a meaningful role for themselves in society"). Whoever altered the original Onion piece to make the President Clinton quotes of the original be from Senators Barbara Boxer and Ted Kennedy is probably responsible for turning an obvious satire into an urban legend. I can't hear President Clinton talking this way. Except for one bit, the quote attributed to Senator Boxer in the later version sounds just like her, and Senator Kennedy has acquired a reputation for a willingness to say anything without giving any indication of meaning it. Besides, there are some words in there that sound designed for his accent.
It struck me as funny too, until I relised the deeper irony of thinking it didn't apply to me, having the obvious above average abilities. I hope they pass the bill. I could use the help. Oh, I forgot...I'm an ex-pat. There, that proves the point.