“Gee, I know a large number of very liberal people, and not a single one of them finds the idea of Christmas trees objectionable. I personally tend to find myself being very skeptical about sources when they make claims like this that are at odds with what I see around me.”Perfect! The response kept a civil tone, emphasized personal experiences, wasn't directly critical of the other person, but instead used personal observations to express skepticism about a news source. (In this case the “news source” was assumed to be a popular right wing radio show, so I’m probably being overly generous using the term “news source”). This seems to be a great way in general to gently but firmly question over-generalizations and prejuduces at the start of a discussion. The art of civil conversations then becomes finding a productive way to continue the discussion in an open and respectful manner.
(I originally posted this in the Tikkun Daily Blog)