In Delaware all must comply with the no-smoking indoors law that is actually even stricter than California's law - however an employer still has the right to hire only smokers if he/she so desires.
Years back, when I was still fighting in favor of a law to prevent employers from discriminating against hiring/firing for outside of work legal activities I collected a huge folder of help wanted ads that stated "Smokers need not apply" or "only non-smokers need apply."
It still remains legal to do so in Delaware, just as it would be equally as legal to place an ad stating "Smokers only need apply."
I have since changed my stance on that type of legislation - the government needs to stay out of it altogether.
What is the rest of the building or other people on the block complained?