It seems each new week brings another national commotion over news of controversial social media posts that were made in the past—sometimes years ago—by someone who is now a public figure. A major league baseball player has come under fire for bigoted remarks he posted while in high school. A newly hired editor at a major newspaper has faced criticism for a history of ugly comments on Twitter. And on it goes. The statement may or may not have been deliberately offensive. The person may or may not have changed his thinking since then. Regardless…