Why does Bill O'Reilly support Bristol Palin, but not Jaime Lynne Spears?

Last week, Jon Stewart did another of his favorite tactics: playing two clips of a public figure saying contradictory statements. He did this for Bill O'Reilly who said in one clip that Bristol Palin's teen pregnancy was a privatre matter, not the subject for public judgment. In the other, earlier clip, Bill O'Reilly places harsh judgment on Lynne Spears for her pregnancy.

This seemed an open-and-shut case of Bill contradicting himself. But he tried to defend himself. He said that the two pregnancy situations were different because there was "well documented" media evidence that Lynne Spears, as well as Britney, were inadequately supervised by their parents and engaged in all the reckless behaviors we've all seen them do on camera. Palin's family, on the other hand, has not shown any such evidence of reckless teen behavior and/or inadequate parental supervision. It does seem fair to say, that when one of Bill's critics was confronted (also at that link), she had a hard time responding to the question: "do you think the Palin family and Spears family are the comparable, given what we know about the Lynne and Britney's bad behavior". She kept sidestepping the question, and saying "I was just trying to criticize Bill, and I stand by that criticism...I'm going back to my chores now".

Not a fine moment for her. However,

There's still problems with Bill's defense. I can accept that the Spears' family lets Britney and maybe Lynne run wild, and that all the media footage we have on them - with their insane behaviors - is true (as far as we can tell).

I can also accept that we don't have any such media footage of the Palin family/daughters doing this similar recklessness.

But if, we assume that the Palin family was responsible, we still have Bristol's teen pregnancy -out of wedlock, illegitamite, whatever term you want for an unmarried teen mom.

So if both the reckless family and the responsible family can have a teen pregnancy, how certain can Bill or anyone be in the judgment that Spears' embarrassing film moments are all we need to judge Spears without prejudice?

Moreover, Bill himself said we don't have any on-film evidence of Palin's family's behaviors, so we can't even be sure that my assumption - that Palin's was a responsible family - is correct. They could have been reckless too. And politicians cover up their dirt better than pop stars.

And also, Bristol and Lynne each got pregnant by the same error in judgment: they had unprotected sex (or "sex when they shouldn't have"). How is Bristol's judgment "better" than Lynne's in this regard?

We simply don't know if the Palin family was any more responsible than the Spears, and if they were was it enough? Should we spare the Palins our judgment if they were only 53% reckless and Spears were 78%? Does it have to be 34% Palin and 89% Spears? How far does the gap need to be to justify that Palin's family is off-limits, and Spears is fair game?

By what criterion or standard do we condemn one and spare the other?