First Names

This is really just a random post, but I find it interesting that only female politicians are regularly called by their first and last names. For example, Hillary Clinton, Sarah Palin, Nancy Pelosi, etc. People talk about the Obama v. McCain debate and the Sarah Palin v. Biden debate. I don't think it really matters or makes a difference, but it is interesting, especially since it is only the first name that makes gender obvious when reading someone's name.