No, you don't have any right not to be offended. I am offended by idiocy all the time. I am going to leave in a minute to drive home in the rain. I will likely be confronted by idiocy, but provided none of them actually comes into contact with me, I will have to go along with the flow, if I intend to make it to my destination.
Perhaps folks who are constantly getting offended because someone thinks differently than they do, should take a look and decide if their ideas are defensible? If so, then who cares what the opposition thinks, or says? If not, then perhaps you should take a more critical view of your thoughts/beliefs.
I am a firm believer in the idea that your rights extend right up to, but not beyond my nose, and I, in turn will expect my rights to extend up to, but not beyond your nose as well. This goes for speech as well. And if none of that works for you, then you may want to go with what "The Family Guy" suggested, and just develop a sense of humor.
B.