And why do people fall for it? They're both rhetorical questions really: on a simplistic level they do it to ingratiate themselves and become Mr Worldwide Popularity, the people do it because it makes them feel better about themselves and their country.
I thought you might like some pics of Mr O'Bamasiah's trip to the Emerald Isles:
"There is no-one more Irish than me."
(Click to enlarge)
It's interesting to note that the comments below the article are less than complimentary.
More coverage HERE and HERE.
Meanwhile, back at the ranch ... ...
UPDATE: Just in: Obama's Top Ten Insults