HELP!!!

I am unable to get my text to a medial alignment! I did widen my margins for the blog, but other than that, nothing that should interfere...When I am typing (like now), I highlight for the text to be central, and it shows on the toolbar, but won't appear that way during typing. I thought maybe it would just be on the composition page but show up as intended on the preview or final publish. It's a no-go.
What is happening???