Oh, if you don't mind me chiming in on that topic, last Easter when we were anticipating our family get-together, my husband I vowed not to discuss politics with his very vocally anti-war, liberal brother. Then the brother and girlfriend arrive wearing anti-war BUTTONS. Somehow I got seated at the table closer to this couple, so the strain was more on me, but I managed to say not one word, except to insist that I knew who Barbara Kingsolver was, when the brother mentioned he had met her (she lives in Tucson), and when he asked me if I knew who she was I said "yes", then he started to explain she was an author so I interrupted and said, "yes, I know who she is", and I turned away.
Thankfully the children were to my right, so whenever they started to hold forth I diverted my attention to the kids.
We noticed that while this couple felt free to ascend a soapbox, we felt compelled to keep silent in the interest of maintaining a pleasant and lowkey dinner.
Sigh
On the other hand, I didn't say a word at Thanksgiving even though I knew that Bush had been in Baghdad before we arrived at the family gathering.
My husband says it is the same impulse that drives miscreants to get others to accompany them in their misdeeds. It is a compulsion to get people to validate their opinions, which they deep in their hearts know are wrong.