Obama on Letterman

His comic timing is nothing to write home about.

Wikipedia's explanation of the common mispronunciation of nuclear is as follows:

"The principle that converts nuclear to nucular is founded in the phonotactics of the English language.

1. By assimilation, the [kli.ər] sequence of the word [n(j)uː.kli.ər] becomes [kljər] in natural speech.
2. The consonant cluster [klj] is strongly disfavoured in English: English stops are followed by one approximant at most.
3. The disfavoured cluster [klj] is reduced. That reduction is achieved through metathesis ([l] and [jə] are swapped so that [kljər] becomes [kjəl(ə)r])."

As if that makes any sense. Nice try, wikipedia.