On his radio show, Rush Limbaugh made the argument that many Democrats move from roles in media to roles in politics, and that this route is not an option for conservatives. Conservatives, Rush argued, go to Fox after they are done with their political careers and seldom go back into politics.

LIMBAUGH: I have no doubt that that's what Chelsea Clinton to NBC is all about: learn about television for a later professional career. Now, this is an avenue not open to conservatives. It is an avenue not available to us. At least, not with any of the big three networks. I guess you could say we go to the media after we bomb out in politics, and we go to Fox. But that's after we bomb out. After we lose our elections, that's where we get hired by Roger Ailes, and so forth and so on. But seldom do we go from Fox back to politics. I could be wrong about this. I'm trying to think off the top of my head if that happens, but we do know that Chelsea Clinton is going to go from NBC to politics. There's no question about it whatsoever in my mind.

Limbaugh is correct that some Fox commentators are former politicians who have lost elections or left politics -- Sarah Palin and Mike Huckabee are prime examples. However, if he is having difficulty calling to mind Fox figures who have made the leap back to politics, he need look no further than the current Republican race for president. Two candidates, Rick Santorum and Newt Gingrich, were formerly on the Fox News payroll. Another example is Tony Snow; the former George W. Bush staffer and original host of Fox News Sunday left his Fox News Radio show to return to the White House as press secretary.

John Kasich, the current governor of Ohio, formerly hosted a show on Fox News. He left the network in 2009 when he announced his run for governor.

Leaving Fox to try your luck in the political arena hasn't always worked out as well as it did for Kasich. Fox commentator Angela McGlowan left Fox to run for Congress and lost badly. But not to worry -- she is now back on the Fox News payroll.

As for Limbaugh's contention that Clinton's path is denied to those with conservative connections, recall that in 2009 NBC -- the same network that hired Chelsea Clinton -- hired Jenna Bush Hager, daughter of former President George W. Bush, as a correspondent for the Today show.