So, for example, if I operated a bus company, and I wanted not to accept, say, jews on my bus, it would be a "terrible decision and a massive step etc. etc." for the state to intervene?
Reductio ad absurdum doesn't work in political matters. Because reality isn't based on simple monotonic logic.
Absolutely reductio ad absurdum works for political arguments. If you didn't think that then why did you literally just use it on my comment? I would say discrimination based on some sort of inherent trait is completely wrong (race, religion, etc) but if a private company chooses to deny service to another private company what affront to civil rights has been committed? I'm sorry but there is no human right to the visa or mastercard network. If you want to support wikileaks send them government issued currency through the government run mail.
Actually, I used reductio ad absurdum exactly to show it can work as a rhetorical device, but in politics you can easily construe "demonstrations" for both sides of an argument using it. So it is not a good argument.
Reductio ad absurdum doesn't work in political matters. Because reality isn't based on simple monotonic logic.