Let's go step by step. You presumably want to keep your blog up and avoid having it connected with you as an employee. Right now, someone will take your opinions as racist and write to your company about it; alternatively, someone will Google your name and figure you're not worth keeping around.
I don't advise just taking your blog down. That would leave caches and archives that might come up. It's safer to replace it with something that can't easily be traced to you.
Pick a pseudonym that isn't easy to associate with you. (D. Joe is right out.) From now on, that's your blog identity. Go through your entire blog, and change your name everywhere. Make sure no trace of J. Doe remains.
Consider doing a cosmetic makeover at the same time. On the one hand, it won't look like you're just changing to a pseudonym. On the other hand, if someone has been taking time to become angry, and the blog's changed, that person is likely to notice the cosmetic change while possibly missing the pseudonym change, and you don't want that person digging through archives.
If you're using a custom domain name (like JDoe.org), changing it is going to be more of a pain, but you can do it. Your registrar may offer a way to keep the administrative contact private. Take it.
If the blog URL contains part of your name in it, things get more difficult. You need to move the blog to a safer URL. You've probably got readers by now, so see if you can put in redirects to the new URL, warning your readers that the redirects will go away. (As long as you've got the redirects on a URL findable by your name, you have a pointer from you to the blog.) Eventually, replace the redirects with innocuous content, possibly a statement that the blog has been removed. That will eventually hit the caches and archive.
At that point, starting with your name and going to your blog is going to be difficult. You can't get the old pages out of archives, so don't worry about them, and that's the only link. Someone coming across your blog will be offended, but won't know where to go from there (unless they decide to search archives, which you can't stop).