One poll a trend makes?

As of today, all polling firms listed at PollingReport.com show President Bush's job approval rating has improved since early November. Nevertheless, KMBZ on December 14 cited a single Zogby International poll as evidence that Bush's approval rating was dropping again. By the way, Zogby's polling numbers prior to the 2004 presidential election were so bad that National Review concluded that pollsters such as Zogby "deserve to be mocked at every public appearance." See http://www.nationalreview.com/kerry/kerry200411031159.asp.