It's Thanksgiving in North America and the Norman Rockwell-esque ideal is that family members will come together and have a wonderful time. Often the reality is different, as people who in some cases have opposing world views get together and, especially after a glass of wine or two, or three, express those views with great certainty. (This wasn't the case in my small family but I've been present on a couple such occasions.)
That reminded me once again of the most useful phrase I've ever learned. I've seen it attributed to George Bernard Shaw, Mark Twain, H. L. Menken, Wolcott Gibbs, Alexander Woollcott and Dorothy Parker. With that many sharp minds as candidates, you know it's got to be good. It is:
"Dear Sir/Madam, You may be right."
One or more of the aforementioned people used that as their standard answer when sometime took exception to their work or politics.
Once in a blue moon (or less often, I'm not sure how often a blue moon comes around) you may find yourself in conversation with someone who has an open mind. In that case it can be worth going into detail about your ideas, listen to the other person's, and it's just possible that one or both of you wll change your mind.
Most of the time, however, this kind of conversation consists of two people each waiting for the other to pause so that they can be persuaded of the foolishness of their ideas. Sometimes it turns quickly into an acrimonious debate and the only thing that changes is the level of regard they had for each other.
The prescription: listen for any signs of intelligence in their comments and, if finding instead that you are hearing nonsense, pause and say, "Hmm, you may be right. Excuse me, I must go and speak to Uncle George/ check the turkey/ catch up on my email."
It can be hard to do this when you are so sure they are wrong and you are right. Isn't it your duty to change their minds? No, it's your duty to catch yourself when you feel that way, lest you become too much like them.
Also, it'll free up time to go have another drink and read something by Shaw, Twain, Menken, Gibbs, Woollcott, or Parker, which will be much more rewarding.