Hardly a week goes by without some demand for an apology populating my inbox. I have never apologized for two reasons: The usual one is that I’m not sorry. The other is that calls for an apology have become an irritating tactic in American political discourse, a kind of bullying.That doesn’t mean I haven’t regretted things I’ve said or the tone used. I have. So here’s a compromise: I will issue one apology a year.And the winner for 2015 is … Bernie Sanders.