Are Offensive Halloween Costumes Ever OK? [POLL]

OK... So I'm mad. I've been seeing Halloween costumes all over the place, and don't get me wrong I LOVE THE SEXY STUFF!! The controversial costumes are really making me itch. I am not the guy who's gonna go to a Halloween party in a Mexican outfit with the sombrero, to me that's offensive. Now for some reason, this year our youth have gone really offensive with the costumes. Just look at these, click the buttons:

The Jackie Kennedy one for reason really ticked me off... but listen. I don't feel these types of costumes are ever OK. What do you think??