As for other aspects of his complaint:
it punishes people for being alcoholics
In a sense, this may be accurate. Alcoholism is a disease, of course, and I think it’s very stupid to punish people for displaying symptoms of their disease. (I’d just as soon do away with all legal penalties for simple drug possession, for this reason). However, this is a moral argument, not a constitutional one; if it’s constitutional to jail people for having heroin, then it’s constitutional under some circumstances to jail people for having alcohol, or for having broccoli.
Is he being singled out for his alcoholism? Without knowing the details, I’m skeptical: it seems likelier to me that he’s being singled out for his illegal behavior that involved alcohol. Just as a criminal who committed a crime with a gun may be denied the right to carry a gun, a guy who commits a crime involving alcohol may be denied the right to carry alcohol. (Again, I think it’s a weird law, but the question isn’t whether I think the law is weird).
Does the law divide people into alcoholics and non-alcoholics? Apparently it does, by referring to “habitual drunkards.” That seems unnecessary to me: the law should criminalize verbs, not adjectives. If he habitually breaks public-drinking laws, that’s subtly different from his being a habitual drunkard. However, the phrase “habitual drunkard” may simply mean “a person who has been arrested three or more times for the following list of alcohol-related offenses,” in which case, I think this complaint would be specious.
Does the law treat alcoholics more harshly? I doubt it: there are a bajillion alcoholics who are allowed to buy alcohol, by virtue of not committing alcohol-related offenses. What it treats more harshly are those who commit said offenses, and I don’t see where this is unconstitutional.
That brings me back to the last complaint: it sounds as if he might be saying that his offenses (public drunkenness) is only due to the fact that, because he’s homeless, he cannot commit private drunkenness. That’s a good point, I think, and it speaks to the social ill of homelessness. But the solution is to find roofs, not necessarily to allow public drunkenness.
If his complaint were that public drunkenness laws were unconstitutional, I’d actually have a little more sympathy.
Daniel