When trump says “China” it sounds like Ch-eye-na as in “eye” and drawn out. Is that a common pronunciation in NY or more unique to trump?
It is the may he pronounces it every time I’ve noticed and it always sounds off. I, and my experience with others saying China is the long eye sound but not drawn out.
I hear it more as “dj-EYE-na” as in “vagina”. One brother-in-law had a NYC accent (Gov. Cuomo sounds just like my late BiL) and I don’t recall him pronouncing it that way.
I am a New Yorker. It is unique to Trump.
That is a good description of how it sounds. IMHO, Alec Baldwin on SNL exaggerates only slightly how I think trump pronounces the word.
I lived in or around NYC for 25 years. Never heard it before.
And then there’s “that Rusher thing.”
Not NY. Just him. I suspect he does it on purpose, to make fun of them.
I doubt that any native Chinese would even notice if he pronounces it differently. They call their country Zhōngguó (Jong gwoh) although there are several variations.
Except of course those who also speak English. It’s a uniquely Trump thing- I’ve never heard anyone in New York say it that way, and I suspect he himself didn’t always say it that way.
I grew up in NYC and don’t recall hearing anyone pronounce it that way.
Aside: I was watching an early Law and Order episode last night. There were cops and a few potential eyewitnesses milling around a homicide scene. Lenny points to a gormy-looking street person and says to his partner, “We gotta go interview Trump over here.” 
He has an under bite. Stick your lower jaw out and say “China” in a sentence. It comes out more or less “jye-nah”.
There is no such thing as a ‘NY accent’, which is demonstrated in general by Trump who speaks fairly differently than the stereotypical working class NY Italian American accent that many Americans know as ‘the NY accent’ from TV and movies. There are only relatively vague similarities in accent which run across all social classes, generations, ethnic/national groups and parts of the City. However, I am from Queens like Trump, like him neither Italian nor Jewish (two distinct variations of local accent at least traditionally), only around 10 yrs younger than he is, and a number of his and my pronunciations are similar. But the funny way of saying China is not one of them. It seems unanimous: that’s him.
Odd China sound is simply Trump.
Yeah, I think it’s this.
There’s a tradition among certain subsets of Americans of mis-pronouncing the names of various ethnicities and countries, and they almost always involve over-pronouncing the first syllable. “A-rab”, “EYE-raq”, “EYE-ran” are the ones that stand out in my memory.
Don’t forget Eye-talian.
I’m from the West Coast and broadly speaking East Coasters including NY pronounce some words differently.
That said, I think it’s pretty overwhelming that the way trump pronounces China is not common.
I too suspect he is deliberately doing so. Probably started so long ago its now encoded in his DNA.
To my ears, it is very akin to Eye-talian and meant to denigrate. YMMV
Gov. Cuomo said “China” several times talking to his brother on CNN. His pronunciation was perfectly normal.
A bit old, but here is a montage… 
I don’t mean this as a dig but I’ve always taken it as a derisive sneer. I think it’s an affectation. A couple days ago, Trump said China twice almost in a row. The first had some of what’s described in the OP (not the full) but the second has none at all.
Jump to 25 seconds in case it doesn’t load properly:
Agreed 100%. He says it like a petulant, bullying child.
There is a general northeastern accent but it covers a big area of the country besides NY. A lot of people from the NY area don’t have close to the TV/movie ‘NY accent’. I lived in LA and San Diego for some years, and nobody ever said ‘you sound like you’re from New York’. Only real accent aficionado’s can pick up that I’m from NY. And don’t recall many people there even picking up that I was from the East Coast. People in the South know I’m a Yankee obviously. But I doubt based on experience there’s really a West Coast accent to the extent the average person there can tell from speech that people come another (non-South) part of the country with much accuracy. Also the accuracy or usefulness of accent analysis has declined as % of people in the US born in other countries, plus those who grew up in households of immigrants, has risen. Queens where I’m from is majority foreign born now, so a ‘Queens accent’ (which some people claim exists as distinct even from ‘NY accent’) is more doubtful still.