We are a commune of inquiring, skeptical, politically centrist, capitalist, anglophile, traditionalist New England Yankee humans, humanoids, and animals with many interests beyond and above politics. Each of us has had a high-school education (or GED), but all had ADD so didn't pay attention very well, especially the dogs. Each one of us does "try my best to be just like I am," and none of us enjoys working for others, including for Maggie, from whom we receive neither a nickel nor a dime. Freedom from nags, cranks, government, do-gooders, control-freaks and idiots is all that we ask for.
It's a real NYC expression of surprise, not for the effete. Can be good or bad surprise. It can also be used for sarcastic surprise, as in "Hillary fell down the stairs holding a cup of coffee? Oofah."
That's what I first thought when I saw the word, was he trying to say uffda. And it's never a good surprise. If it is particularly unpleasant, my grandmother would say, "ish," short for ishda. There's no translation; these are true expletives.