In all honesty, I don’t have much of a problem with this if that’s the way he’s been saying the country’s name his whole life. I’m from Boston and I say VaMont, not VerMont and Missouri instead of Missura (as my cousins say it).
Obama has lived in Hawaii, California (Occidental), New York (Columbia), Massachusetts (Harvard), and Illinois, off the top of my head.
How could he have been using that pronunciation his whole life?
No one in any of those states says POCK-ee-stahn, except maybe a few pathetic losers at the Kennedy School of Government. And you know their mamas don’t say it like that.
It’s not a regionalism like Missura; it’s strictly an affectation, pointedly meant to shame Americans and emphasize The One’s sophistication.