I’d like to know if we can list what people are called from all 50 states and Canadian Provinces.
People from -
California - Californians
Arizona - Arizonians
Alaska - Alaskans
Rhode Island - Rhode Islanders
Vermont - Vermonters
Texas - Texans
What are some of the hard ones…Like Nevada and the Carolinas?
We are Nevadans.
North or South Carolinians, perhaps?
Ohio - Ohioans
Florida - Floridians
Proud Michigander, here.
The people I know in Maine call themselves Maniacs, but other people seem to call them Mainers.
Mainers, Ohioans, Nevadans.
I thought you all self-identified as either a UP’er or Troll!
I never could get a good concensus on what we folks from the great state of Connecticut should be known as. ‘Nutmegger’ was a popular choice, but of course that means nothing to people from outside New England. I always thought ‘Conneticutian’ had style, but no one else seemed to like it.
Hawaiians
Wisconsinites
Iowans
Oklahomans
Washingtonians
Prince Edward Islanders
Quebecians and Quebecquois (not sure of the spellings)
Kansans
Georgians
Glad to see “Michigander” is still out there. When I lived in Michigan there was a huge public debate over whether we should be Michiganders or Michiganians. It seemed like Michiganians got adopted broadly but I was always a one-boy pocket of resistance.
Someone once told me that people from New England call people from Massachusetts Massholes. Any truth to that?
It depends on who’s doing the self-identifying. “Trolls” is what **Yoopers ** call us folk who live “under the bridge”.
People who work on Mackinac Island - arguably right in the middle between the UP and the rest of the state - call us “Fudgies”. All of us. And you too, if you go there.
Indiana - Hoosiers
Or, at least, as far as I know. I’ve never heard it any different.
Coloradans or Coloradoans.
Born Texan, living in OKC, OK right now.
Most Oklahomans refer to themselves as Oklahomans, but some self identify as Okies. Yes, at one time a certain other subset of the US called Oklahomans Okies in a disparaging manner, but that old Dust Bowl / Grapes of Wrath meaning seems to have died out entirely. So, either would appear to be okay. ymmv but I’ve never seen anyone take offense at the word.
FTR, I often call many of my Okie friends and family a bunch of cheating land theives. Yep, Sooners. 
Proud Jerseyian here. Or, possibly a Jerseyite. Hmm…lesse what Googlefight has to say on the subject.
Ok, looks like I’m a Jerseyite:
Jerseyite - 6,360 results
Jerseyian - 862 results
I can attest to the veracity of that statement. Indeed - Masshole has emanated from my lips whilst driving on many occasions. It’s just too easy, I mean, how can you not? I even call people from Connecticut/New York and New Jersey Massholes when I experience that sort of driving behavior that so merits the name - I mean “New YorkHole” doesn’t have the same eloquence.
As for people from Maine, Maniac is the informal (to be used with other “maniacs”, Mainer is the formal (to be used amongst people “from away”). That’s my story and I’m sticking with it.
I’m from Connecticut, and you had better not call me a Masshole! 
Connecticut = Connecticutite or Connectican … I think…
New Mexicans - that one’s easy.
I’ve always considered it to be New Jerseyan, or perhaps more commonly, “Those mean crazy scary people.”
Pennsylvanians, of course - another easy one.
“Maniac” is a cute word to use with tourists, but we all agree here that that term is Mainer.
“Here” being the operative word. Different places may have different standards, I can only speak for mine. I could see Maniac being more in use on the tourist-oriented coast.
(“Tourist” is another tourist word. They’re known as “those from away” to locals, and are viewed with much reservation. That isn’t an invention of eastern movies.)