One can be a descriptivist without defending or condoning sloppy usage, as one can be a prescriptivist and practice sloppy usage. Pronunciation shift is a part of language; discounting the contributions of someone whose usages do not match one's own only limits the holder of these prejudices.

"I seen the enemy, and they is us."

And, yet, if we continiue to use the "Dubya" for "double-you", we're all descrptivists, changing the language to suit the need and facilitating a permanency of that change through repetition, aren't we?

What about LBJ's..."Mah fellah Americans"? I know that's is just a matter of accent, but did it render him less intelligent in my eyes...no. Or the Kennedys' thick Boston accent? But I think you also have to know, and in a postition of influence, demonstrate that you know the rules before you break them, linguistically speaking (Creative Writing 101). If you want to write experimental poetry, fine. But, first, you should know and be able to work in the sonnet form before you abandon it. I do think that many politicians streamline their verbalization to reach their greatest perceived number of constituents. And all, of course, are given to the colloquialisms of everyday speech like the rest of us. Witness Dale Bumpers eloquent Daniel Webster-like oration to the Senate during the Clinton impeachment proceedings. If he spoke that way everyday in local Arkansas TV interviews he'd probably never get re-elected. However, I have always reacted to nucular as a mispronunciation...there's nothing there that merits change except for a lack of intellectual guidance, at the least. Not good form for presidents or kings or college professors, etc.

Welcome, Madame Curie...and thanks for discovering radium!