Shotgun argumentation or the “Gish gallop”: the arguer offers such a large number of arguments for their position that the opponent can’t possibly respond to all of them. Usually the idea is that if you cannot refute everything that’s said instantly then they claim “victory”.
Moving the goalposts (raising the bar) – argument in which evidence presented in response to a specific claim is dismissed and some other (often greater) evidence is demanded. For example, they’ll start with something specific – such as separating asylum seekers from their children – and then start wanting to claim that they’re not “real” asylum seekers.
Nirvana fallacy: That’s when solutions to problems are rejected because they are not perfect. For example, “there’s not a good enough solution to immigration reform right now, so why are you harping on what we’re doing?”
Ignoratio elenchi (missing the point): This is when an argument that may in itself be valid, but does not address the issue in question. Example: “It’s possible that some of the people claiming to be refugees aren’t really.”
Ecological fallacy: inferences about the nature of specific individuals are based solely upon aggregate statistics collected for the group to which those individuals belong. “Here’s this one asylum seeker who has done something good/bad; therefore, all asylum seekers are good/bad.”
Argument from repetition (argumentum ad nauseam): This signifies that it has been discussed extensively until nobody cares to discuss it anymore. This has been perfected by Fox News (I’m not being sarcastic here), where they’ll repeat the same thing over and over and over again. This is a variant of “If you tell a lie big enough and keep repeating it, people will eventually come to believe it.”
What’s the solution? It’s twofold.
First, remember that if you’re in public (and a public social media post counts!), your audience is not actually the person you are speaking to, Your audience is all the other people who are watching you debate this.
Second, stick to the point. Do not let your argument be slid off into side disagreements. They will try to get you sidetracked. Resist. Redirect back to your original point at all times. Especially when someone is trying the “Gish gallop” on you, this kind of single-mindedness will prevent you from being taken advantage of.