By default -- as set up by our webmasters in Missouri -- our site allows comments on news stories and on blog entries, but not on anything that's posted as an opinion column. Today, I had two different co-workers ask me why. I couldn't tell them; I don't know. I'll ask our webmasters about it the next time I get in touch with them.
But there is a way for us to change that default on a case-by-case basis, and we're going to start allowing comments on opinion columns. If we forget to flip that switch for a particular column, and you would like to leave a public comment, please let me (email@example.com) or David Melson (firstname.lastname@example.org) know.