My posts get lots of comments, and I read them all, sometimes more than once (OK, I admit, if a commenter writes a short book, I may stop in the middle). I enjoy the heated discussion that goes on in the comments section, and I expect and appreciate comments from people who disagree with me. That's part of the process.
But comments that try to hijack the discussion, frankly, piss me off, and I will begin deleting them, not because I disagree with them but because they're off topic, and their comments either sidetrack or end the discussion.
If I write about candidates in the race for Superintendent of Public Instruction, commenters should write about that race and those candidates, not the TUSD school board race. When I write about the governor's race, a commenter should talk about the governor's race, not his opinion of Obama, in two consecutive posts.
People who don't like the topic of any given post can ignore it. People who desperately want to write about the TUSD race or Obama can start their own blogs and see if they can find an audience, or save their comments until I write about TUSD or Obama. If you go way off topic in a comment on one of my posts, there's a good chance I'll delete it so the on-topic discussion can continue unimpeded.
A word to commenters who enjoy a hearty discussion of the issues at hand. When I was posting on Blog for Arizona, we had a number of people known as trolls, who would do everything they could to short-circuit a discussion or move it in another direction. Our advice there, and my advice here is: Please don't feed the trolls.