Refusal to look at application for employment if you smoke

It is not illegal to discriminate on any basis other than those prohibited by statute, e.g. race, religion, age, nationality, etc.  I know of no statute which prohibits discrimination on the basis of smoking, although it could possibly be argued that this really equates to discrimination on the basis of a medical condition (employers not wanting to pay the higher health insurance premiums they may have to pay for employees who are smokers), which is prohibited under certain conditions.  In other words, you may have a claim, but it's a stretch.