I am sure there are some old bigots out there that said, “Let Negroes marry whites?? What’s next? Men marrying men?”
Wonder if they feel vindicated?
Obviously, I don’t know ytou, and I could be wrong, but I’m willing to bet that you use the same quip on a regular basis, just with a different set of arguments.
Liberals regularly suggest that, if religious conservatives get their way on a relatively minor issue, next thing you know we’ll be living in Iran, ruled by mullahs.
If YOU haven’t made such remarks, I’m all but certain you have liberal, secular friends who have. Do you tell THEM they’re being stupid, too? Why not?
Now why on earth would we bother with that foolishness, when we’ve got that whole First Amendment thing on our side? 
Mr. Tombe married a goat.
Yeah, I debated whether to use the word liberal in my OP, because I definitely don’t consider myself one. I find myself on the liberal side more often than not, but I’m mostly independant and equally annoyed by both parties. In fact I was undecided on the gun control issue because I didn’t know enough about the restrictions, but it was nonetheless an argument I was a 3rd party to and shook my head at.
I’ve personally never heard someone in real life make the mullah rule extrapolation, but I promise you stranger, I’ll react the same way when I hear this type of foolish logic.
There is often (but not always) a valid (but usually not sound) argument hiding behind the commission of fallacies like Slippery Slope.
In this case, the argument can often be reconstructed as:
“By the logic of the arguments people give for X, ridiculous, extreme (and incorrect) conclusion Y ought to be reached. So the argument for X must have gone wrong somewhere.”
I’ve never heard this, not even once.
Not saying it doesn’t happen–I’m sure it does in fact–but it is not even close to being as “regular” as you claim.
I’m not a big slippery-sloper, except:
I’m against flag desecration prohibitions, because what’s next? Banning other forms of non-verbal, offensive political speech?
I think the difference is between pointing out a small extension, which leads to either another small extension or a harm. No sure though, just keep your stinking paws off the First Amendment, you damned dirty apes!
(Oh, same goes for the Fourth, Fifth, and a slew of others. And on Agent Tower’s behalf; the Second.)
I’ve never heard or said it.
The term you are looking for is “slipery slope argument”. Basically arguing against a position by taking a particular stance to its logical extreme.
The counter is argue the merits of the particular item in question and to point out the absurdity of the argument and that A does not necessarily lead to B to C ultimately to Z.
There seems to be a distinctly SDMB sort of thought process that one has to argue or debate with everyone in their personal lives who disagrees with them. Quite frankly, if a person’s mind is already made up over something like God, abortion, gun control, smoking in restaurants or gay marriage, chances are no amount of logic or debate is going to convince them otherwise. Given the number of “my idiot friend says , how do I respond.” You respond by saying “You are certainly entitled to your beliefs and I would appreciate it if you respected mine.”
My response to that is always “Ok…that’d be fine by me. The minute a dog or cat can say its wedding vows, then I have no problem with people marrying them”.
So you want to prohibit the mute from getting married,eh? 
You couldn’t even be bothered to make it to the second post in the thread?
Hmmm…somehow I completely missed that.:smack:
In my experience, anybody who uses this argument in respect to gay marriage is merely being disingenuous and has no interest in any kind of honest debate or discussion anyway.
That said, on occasions when I’ve attempted to engage people who take this tack, I ask them what they think would be wrong about, for instance, a woman marrying a dog. Does that same objection that applies to dogs apply to other women? If not, then there’s reason for allowing one and not the other.
Ah, it happens. Upon rereading my post to you, I sound awfully snarky and didn’t mean it that way. I hope I didn’t offend.
Meh…it’s not like we’re dating.
Hal’s on the right track with this one. Take the argument seriously. Next time you hear it, say something like this:
“Okay, let’s say that we do legalize marriage to animals. What practical effects will this have? Animals cannot own property, so they won’t be able to inherit. They don’t have the intellect to make legal decisions, so they won’t have power of attorney. For the same reason, they won’t be able to make next-of-kin decisions about health care for their spouse. On the other side of the coin, a person already gets to make all these decisions for their pet just by the simple fact that they own the animal. So lets lay aside, for the moment, that no one anywhere is pushing for the right to marry their pet, and therefore, there is absolutely no reason for anyone to write this legislation in the first place, and let’s pretend that this law actually gets passed. So what if it does? It’s going to be an ineffectual and meaningless contract that has no legal effect, and changes nothing at all.”
Next thing you know, the goats will want to vote!
When I was a kid (more years ago than I want to think about, but it was befoe drugs were much of an issue) there was a frequently raised argument against chewing gum. If you chew gum, that will lead you to smoke and smoking will lead to drinking and drinking to sex, so if you chew gum you will become a sex fiend and that leads to damnation.