Nancy Friedman asks, “Is Charles Pierce the only U.S. journalist who uses gobshite?” She provides a link to an Esquire Magazine politics blog post by Pierce, titled “What Are the Gobshites Saying These Days?”
I was not familiar with the term, but having previously covered gobsmacked (wherein gob means “mouth”) and shite, I could figure out that it means someone out of whose gob comes shite. The OED confirms the meaning and notes that it’s “chiefly Irish English” and (thanks!) “derogatory.” The first citation is from Hugh Leonard’s 1973 play “Da“: “Hey God, there’s an old gobshite at the tradesmen’s entrance.”
(Interestingly, the OED reports an earlier U.S. Navy use, meaning “enlisted seaman,” with this 1910 quote: “You can imagine all the feelin’s In a foolish ‘gobshite’s’ breast.”)
In answer to Nancy’s question, I would have to say, actually, yes. When I searched for the word in the Lexis-Nexis database of U.S. newspapers, going back to the 1980s, I was initially surprised to find fifty-six hits. But a few were references to or quotes from Ireland, and most of the rest were references to a New England-based band called The Gobshites. The most recent, from August 2012, was a quote from a”political observer” named Charlie Cooke. He was discussing, you guessed it, Charlie Pierce:
“Pierce’s hyperbole transcends mere disagreement, as does his dismissal of all those who dissent as ‘gobshites.'”
notoneoffbritishisms.com 
gobshite is more a description of character than a reflection of someone’s discourse. Gobshiteness encompasses more than simply talking shite, it implies a loquaciousness, lyrical style, opinion stating with premises not always supported by solid evidence.
Charles Pierce responds: http://www.esquire.com/blogs/politics/brief-liguistic-interlude-gobshites-012913
Well, I saw “Da” on Broadway back then, so I must have heard the word before, but I can honestly say that I don’t think I’ve heard or seen it since, until now. Trying to find an “official” definition, I ran across this article of possible interest: http://itre.cis.upenn.edu/~myl/languagelog/archives/004633.html .
It’s a fairly popular term in Ireland. Insulting, yes, but like many Hiberno-English pejoratives it’s also occasionally used with some affection (as for example when someone you’re fond of is too generous or compliant, or is simply talking rubbish). More often, though, no affection is intended, and the word serves more generally to refer to a “fool”, a “useless eejit”, or someone talking shite.
Etymologically, this English gob may have come from Irish gob “mouth, beak”. Bernard Share, in Slanguage, mentions British dialectal gawby, gooby, etc. for comparison, and notes the excellent nominalisation gobshitery, which might translate loosely as “stupidity, nonsense, eejitry”. It has common currency in politics, where we have no end of said behaviour.
It’s worth searching for “gobshite” on IrishTimes.com for some colourful recent examples of the word in use.
A couple of years ago there was an Irish Daily Times front-page headline about their own Government that said simply: USELESS GOBSHITES (with the subheadline “Government in meltdown but STILL they cling to power”). This might have got a bit of international attention.
Irish Daily Star. Dublin edition of the (London) Daily Star, a lowbrow tabloid.
“Gob” is also scottish, from Gaelic, scots or irish, for “mouth”
“…this English gob may have come from Irish gob …”
A long time ago, surely. (“gobstopper”, “shut your gob”, etc”.)
In my head I hear “gobshite” in a Glasgow accent. That’s not incompatible with an Irish origin of course.
It is also a very popular term of abuse in Liverpool, a city which, like Glasgow, has strong Irish connections.
It is also a Liverpool expression and dates back decades. My father used to use it when irate. My mother who was more genteel would wince if she heard him use it which she seldom did as it was not considered a word to be used in mixed company. It has nothing to do with loquaciousness or talking nonsense. A gobshite is a expectorated lump of saliva. To call someone a gobshite is to equate them to such a lump. I have never heard it used affectionately. I have met several.
Why is an expression used almost exclusively in Ireland by Irish people listed as a “Britishism”?
I’m English and have heard it as far back as I can remember – in England!
I am always amazed at otherwise rational scholars and commentators who are so married to the Britain-first-against-all-evidence view of etymology, history and culture that they cannot simply say, “The term comes from the Irish ‘gob’ meaning mouth and ‘shite’ meaning shit, and is, in combination, a very common term in Ireland for an insufferable know-it-all who doesn’t actually, you know, like scholars who think every word in the English language derives from Latin or British dialects and never from that barbarian Ireland and its deeply creative and colorful and musical dialects of English mixed with the Gaelic that is still spoken there. And Dia forbid we ever acknowledge that a great deal of slang spread out from Ireland with the diaspora, largely forced out by the colonial power that then laid claim to all the slang the way it laid claim to the potatoes.
The word makes a startling appearance in the Saturday Evening Post version of P. G. Wodehouse’s long story “The Crime Wave at Blandings” (1936). His language is in general family-friendly, especially before the Second World War; only afterward would he use the word “bastard”, preferring “child of unmarried parents” and similar locutions. No other version of ‘shit’ or ‘shite’ appears in his published fiction. So I’m puzzled about the following, and wonder if some editor at the Post may have inserted this one.
In all other editions of the story, young George Threepwood, grandson of the Earl of Emsworth, sees his prospective tutor Rupert Baxter (formerly Lord Emsworth’s secretary):
“Looks a bit of a blister,” said George critically.
But in the Saturday Evening Post, October 10, 1936, p. 6, George’s reaction is “Looks a bit of a gobshite.” Seems out of place in Wodehouse and the Post, but there it is.