I have to vote for California, although it's not on your list.
Here in SoCal it's IMPOSSIBLE to do anything or go anywhere without seeing veg*n restaurants, stores, fast food places, etc.
Regarding Texas: When I went veg in 1988, I was living in Dallas. Talk about a MISERABLE environment for a compassionate lifestyle.
EVERYTHING had dead animals in it, from green beans to potatoes and everything in between. We were constantly explaining to restaurant servers that, no, taking out the chunks of animal flesh from an order of green beans does NOT magically make it vegetarian.
However, I see that Austin is on your list. I understand that it has turned into something of a veg*n oasis in its otherwise meat-oriented state. So if you're okay with a state that has an ultra-conservative political and social climate, but can live in its one bastion of forward thinking and veg*n friendly, Austin, it should be a good choice!