Linguistically speaking there's an
interesting page at Berkley that discusses this pronunciation and also whether or not W is doing it on purpose as well.
I like the faux-bubba explanation. Pronunciations like that probably do resonate with the kind of folks who have "hot water heaters" in their homes and trailers.
a little bit from the page:
But it isn't always easy to tell whether an error is a typo or a thinko. Take the pronunciation of nuclear as "nucular." That one has been getting on people's nerves since Eisenhower made the mispronunciation famous in the 1950's. In Woody Allen's 1989 film Crimes and Misdemeanors, the Mia Farrow character says she could never fall for any man who says "nucular." That would have ruled out not just Dubya, but Bill Clinton, who said the word right only about half the time. (President Carter had his own way of saying the word, as "newkeeuh," but that probably had more to do with his Georgia accent than his ignorance of English spelling.)
On the face of things, "nucular" is a typo par excellence. People sometimes talk about Bush "stumbling" over the word, as if this were the same kind of articulatory problem that turns February into "febyooary." But nuclear isn't a hard word to pronounce the way February is -- try saying each of them three times fast. Phonetically, in fact, nuclear is pretty much the same as likelier, and nobody ever gets that one wrong. ("The first outcome was likular than the second"? ) That "nucular" pronunciation is really what linguists call a folk etymology, where the unfamiliar word nuclear is treated as if it had the same suffix as words like molecular and particular. It's the same sort of process that turns lackadaisical into "laxadaisical" and chaise longue into chaise lounge.
That accounts for Eisenhower's mispronunciation of nuclear, back at a time when the word was a new addition to ordinary people's vocabularies. And it's why Homer Simpson says it as "nucular" even today. But it doesn't explain why you still hear "nucular" from people like politicians, military people, and weapons specialists, most of whom obviously know better and have been reminded repeatedly what the correct pronunciation is. The interesting thing is that these people are perfectly capable of saying "nuclear families" or "nuclear medicine." I once asked a weapons specialist at a federal agency about this, and he told me, "Oh, I only say 'nucular' when I'm talking about nukes."
In the mouths of those people, "nucular" is a choice, not an inadvertent mistake -- a thinko, not a typo. I'm not sure exactly what they have in mind by it. Maybe it appeals to them to refer to the weapons in what seems like a folksy and familiar way, or maybe it's a question of asserting their authority -- as if to say, "We're the ones with our fingers on the button, and we'll pronounce the word however we damn well please."
But which of these stories explains why Bush says "nucular"? Most people seem to assume he's just one of those bubbas who don't know any better. But that's hard to credit. After all, Bush didn't have to learn the word nuclear in middle age, the way Eisenhower did. He must have heard it said correctly thousands of times when he was growing up -- not just at Andover, Yale, and Harvard, but from his own father, who never seems to have had any trouble with the word. But if Bush's "nucular" is a deliberate choice, is it something he picked up from the Pentagon wise guys? Or is it a faux-bubba pronunciation, the sort of thing he might have started doing at Yale by way of playing the Texas yahoo to all those earnest Eastern dweebs?
