Wow! I'm shocked you would even consider deleting the comments. Keep the debate focused on what belongs in a classroom - not on what constitues a valid comment to your blog. Keep your comment thread as a resource - after all, you can't engage in good conversation if you're not listening to the other side.
I think I would stop reading if I knew you were deleting comments you thought were incorrect. Your revealing info about Emily's blog makes me much less inclined to spend time there.
I'm not interested in censored views.