Do you discuss politics with your clients?
When first being interviewed by a client, and vice versa, I am always sure to let each potential client know that I run a business, and all if any casual conversation should always be about the goals that have been set. I work with a few friends,as well, and I treat all clients the same. The time my clients have paid for is time that is spent working towards achieving these goals.
Also, to engage in a conversation with a paying customer, that may ultimately lead to an argument,(politics, religion, abortion), could lead to loss of a client. I would avoid all conversation that people become passionate about.