No, not if they are peaceful, otherwise the answer is yes.

It's not just sleeping, its defecating, starting forest fires, setting buildings on fire, littering, stealing shopping carts, drug use, crime, untreated mental illness. All of these things are bad for society, especially the so called homeless, and must end. Liberals are not helping situation. FJB

That would require a convention of states. Good luck with that.

Does that include sitting on a bench and dozing off?

Nope, but it would be a help if rent would be affordable and people could actually get jobs instead of discrimination against them . And it would definitely help against crime and stuff.