Conservative women in the media are generally more attractive than liberal women (Fox vs MSNBC etc)
Thats not necessarily because conservative women are more attractive - it could be that Fox puts way more points on a woman's looks in the hiring process. There certainly is a certain look and voice that most Fox anchorwomen tend to have, while MSNBC has more variation.
That's entirely the reason. Fox News used to have a "no-pants policy" for their women. I guess that all changed when they hired Jeanine Pirro...she's ugly on the inside so I have no qualms about mocking her appearance on the outside too.