Ron Paul is the Rodney Dangerfield of Republican presidential candidates. The 12-term Texas congressman ran for president on the Libertarian Party ticket in 1988 and was widely seen as a sideshow in 2008, despite finishing third in the GOP field behind John McCain and Mike Huckabee. Why, despite a small but devoted set of supporters, does this 76-year-old obstetrician turned politician routinely get no respect from the media and GOP operatives? Let's take a look at what "Dr. No" — a nickname grounded in his medical career and his penchant for voting against any bill increasing the size of government — really stands for.

1. Ron Paul is not a "top-tier" candidate.

At some point in the race for the 2012 Republican presidential nomination, the mainstream media became more obsessed than usual with designating GOP hopefuls as "top-tier" candidates, meaning "people we want to talk about because we find them interesting or funny or scary." Or more plainly: "anybody but Ron Paul."