If you put yourself in a drunken state voluntarily I see no problem with a contract standing. Some people can be legally drunk but straight headed and do sound work and thinking, and some people can be out of it and not legally be drunk. Prove “drunk” without blood test or breathalyzer. People can act drunk and not be drunk.
Now if someone drugs you against your will or unknowingly makes a person drunk or high and gets them to sign a contract, that contract should not stand.
By the same token, this guy is seeking out people who are drunk, very purposefully. He’s going to bars, clubs, spring breaks events, because he people are intoxicated. So, it’s not like they are coming to him. If a drunk person walked onto a car lot and sought out a car to buy, I’d see your point. If a car dealership went to a spring break night club, and started trying to get people to sign paperwork to buy a car, that’s still okay to you? A contract is a meeting of the minds. Someone seeking out people who can’t do that properly damages all contract law.