"At the end of the 2008 presidential election, there were eight national tracking polls and many other polls conducted on a regular basis.Polling analyst Nate Silver reviewed the tracking polls and said that while none were perfect, and Rasmussen was "frequently reputed to have a Republican lean", the "house effect" in their tracking poll was small and "with its large sample size and high pollster rating [it] would probably be the one I'd want with me on a desert island."