Do you really think nursing home operators want to allow residents smoking?
I know it's unbelievable to you, but yes nursing home/assisted living home operators are in business to please all the people that pay good money to live in their facility. Contrary to popular belief all old people aren't just plunked into some state home against their will and some of them actually have a good income to pay for any place they wish to stay and they choose their own facility. Nursing home/assisted care facilities owners know that there is a demand for smoking facilities among many of thier potential residents and they will try to fill that demand if possible.
"Do you really think nursing home operators want to allow residents smoking?"
If they don't they are free to ban it in their own facilities. No law is required for them to exercise their property rights.