So, don’t erase a blog post. This is true for all bloggers as it is for political bloggers. Once a blog is published, then it has almost a 100% chance to going live to the world immediate, both with the search engines as well as within RSS feeds.
If you publish something that you later found to be incorrect or event regret. Address the posting; why it was incorrect or even why you regret publishing it. That will create much more of a rapport with your readers than simply deleting the problem.

I don’t know… I’ve personally removed blog posts from my blog – it was after threats of being fired from my job and well worth it!! (yes, I am no longer with that company and yes, I finally convinced the company to embrace blogging)