Why do people say'Nucular' when it's clearly 'Nuclear'?

Question:

Why do people say'Nucular' when it's clearly 'Nuclear'?

Best Answer - Chosen by Asker:

It's a shift of sounds called a metathesis; while Bush's pronunciation is generally not accepted, it has been used by other presidents as well (yep, Bill Clinton did it too), and is in fact a fairly common mispronunciation. It tends to make a person sound less educated when that person says "nucular" instead of "nuclear," but it's not as uncommon as some of us might like to believe. The "nucular" pronunciation drives me nuts, too, but it is out there and even listed in some dictionaries as an alternative pronunciation.