I've read the Fair Housing Act..........I know how it can be gotten around.....and at no time in my life have I ever been a landlord.
I wouldn't be one if anyone paid me to do it.
OTOH, I have been on the tenant end and so know exactly how landlords can get around it. Thankfully I haven't had to rent an apartment in over 15 years, but the last time I did the only only reason I got it was because one of my personal references happened to be the landlady's brother, a fact I didn't know at the time. She later told me she did not want to rent to a 29 year old divorced woman. And she could have easily gotten away with not renting to me.
Now, tell me something I don't know.
My only point was that a landlord cannot just deny renting to anybody for any reason. The fact that landlords skirt the law does not mean that they can give any reason to anybody - it just means they go to greater lengths to discriminate. The fact that loopholes exist - I'm sure people will look for a box not checked if they really want to - doesn't make it right. Discrimination is discrimination no matter how you look at it. You may not like who you are supposed to rent to, but that's the price you pay for being a landlord.
I own several rental units and I have rented to Whites, Blacks, Hispanics, Jews, a Muslim with no problem at all.
However, I do not rent to smokers.