I had better write this down so I can take credit for it:
Kennel's Law of Internet Sarcasm: Nothing you can post on the internet is so stupid that someone won't take it seriously.
The consequences of this simple law are quite profound. It means that you have to be very careful about attempting to use sarcastic humor. Ethnic jokes? Racial humor? Usually not a good idea.
It's too bad. From the time of William Shakespeare, Anglo Saxons have enjoyed making fun of themselves and laughing together. I am not Anglo by blood, but I've grown up in America, so culturally I'm pretty much tuned in to their way of thought. I let you make fun of me, you let me make fun of you, and we are both jolly good fellows. We are willing to let our guard down with each other. However, not all cultures are like that!! Some cultures assume you mean what you say, and insults are insults.
In 1729, Jonathan Swift wrote "A Modest Proposal" in which he suggested that poor Irish people should sell their children as food to rich English people. This was satire. Swift's point was that the English upper class were way too rich and draconian in their approach to their Irish neighbors. They should have come up with some reasonable plan to help ease unfair economic conditions involving Irish people. Most readers got the point and were sympathetic to the cause of the oppressed Irish people, or at least put off by the draconian aristocracy mocked by Swift's satire.
Nowadays, if this were published online, someone would think that Swift was seriously proposing that Irish children should be eaten by rich English people. This would be standard fare on AM radio. Some people would get very offended, or worse, others would think it is a good idea. It's hard to imagine Democrats and Republicans agreeing on anything, so one party would probably wind up supporting it.