Politicians, pro athletes, entertainers and actors/actresses in general as life-style role models for kids is a danger anyway. Their job is not to be a morality model, but to perform specific duties and do specific tasks. Being a role model doesn't fit. Examples:

Pres. Bill Clinton - his personal behavior on-the-job was sickening, but many folks thought he was okay as a President. In fact, there were many who thought his impeachment was really about the Lewinsky matter, and believed that "wasn't fair."
A signficant number of the NBA and NFL superstars - Either have criminal records for everything from dog-fighting to drug running, and that doesn't include the number fathering children out of wedlock and dumping responsibilities later. Yet, they keep having their pictures on cereal boxes and get paid to endorse products marketed at the young.
U.S. Congresspersons - The list of these elected officials with ethics violations is scary. The behavior of many when away from the "home folk" and enjoying what DC has to offer parallels the ditties written about mariners-of-old on shore leave.
Sen. Ted Kennedy - I could go on for days on this dude, but he keeps getting re-elected.
Vice. Pres. Spiro Agnew - The only V.P. ever to resign because of criminal charges. That speaks volumes.
"____________" - Fill in the blank. This list could go on ad infinitum.

The bottom line is that if you want a President or Vice President or any other elected official to be the poster boy/girl for your concept of morality and example to your kids of "being perfect," no one will ever qualify.

So, if Gov. Palin (and her family) is being held to standards which were not applied to the aforementioned elected officials and those who entertain us for money, then there is indeed a double-standard being applied to her.

Whether the double-standard is because she is conservative (that's politics and expected) or is a woman (that's sexist and shameful), it doesn't say much for the so-called concept of "progressive liberal thought."