Surprising that TN is leading the way here. Constitutional carry makes sense. While I personally think that training is a good thing, I don’t think it should be a requirement for exercise of a basic right. I think John Lott looked at the question and came to the conclusion that the required training didn’t make much of a difference from a macro perspective.
The big question is Arizona. VT has had Constitutional carry since the early 20th century and AK has had it for I guess about 5 years. Both states are thinly populated without any really large metropolitan areas. When AZ goes on it’s merry way without “blood running in the streets” for a couple of years, you’ll see other states adopt Constitutional carry.
Why? The TN that I have lived in all my life is very pro-gun/pro-2nd Amendment. Not as much as Vermont maybe but we would like to be.