Editor’s Note: Joan Steinau Lester is the PEN award-winning author of six books, most recently “Loving Before Loving: A Marriage in Black and White.” The opinions in this commentary are her own. Read more opinion at CNN. CNN — My wife and I were recently invited to Thanksgiving dinner at the home of a friend. At the bottom of the invitation, printed in bold letters, were the words, “No Politics Discussed.” Joan Steinau Lester Courtesy Irene Young I read those words with a deep feeling of relief. “No Politics Discussed” would — as the hosts no doubt intended — foreclose...