Sarah Palin's interview this morning on Fox News Sunday again exposed the central problem Fox News has in maintaining a stable of once and potentially future Republican candidates, officeholders, and strategists: how can you expect honest analysis from contributors who have the ulterior motive of trying to maintain their own political viability?

In this particular case, host Chris Wallace asked Palin about whether she is considering a 2012 presidential campaign... moments after he asked her to put on her “analyst hat” and handicap that race.

Asked who the frontrunner is for the GOP nomination, Palin replied, “I have no idea.” After Wallace told her that such a response indicates that she's “not a very good analyst,” Palin added, “Fire me then, Roger [Ailes]. Sorry, I already failed.” And yes, she did, but so did Ailes in hiring her.

How exactly is Palin supposed to respond to that question? Everyone and their dog knew when Palin was hired that by Fox that she was considering a presidential run. So Palin has two options: She can talk up someone who may be a potential opponent, or she can talk down those potential opponents and boost her own stock. Fox News has created a situation in which it is impossible to determine whether their contributors are actually trying to provide strong analysis of the political landscape, or whether they are trying to help themselves.

And it's not like Palin is unique in this respect. Rick Santorum, Newt Gingrich, and Mike Huckabee are all Fox News contributors or hosts who are considering a run for president in 2012. Former Bush administration officials Karl Rove and Dana Perino appear regularly on the network to burnish their old boss' - and thus their own - legacy. Dick Morris uses his Fox News appearances to fundraise for political organizations with which he is affiliated.

Minutes after Palin's speech at the National Tea Party Convention last night, poor Mike Huckabee was asked to comment on how she “electrified” the crowd there:

You can almost see the gears turning in his head as he tries to figure out how best to respond. Trash Palin and risk the ire of her supporters? Praise her and risk the clip ending up in a future Palin 2012 primary campaign ad? The Fox News Shadow Primary is shaping up to be an awkward one; the networks' viewers will surely not benefit from such a sideshow.