You're right - except here's page 1 of Google's "Obama 57 states":
So what you're saying is, 'let the right milk it with Democrats, but not the other way'.
Oh, and here's Page 25 - yes, 25:
Note, the top entry is... a comment defending, you guessed, Sarah Palin from a gaffe last month, by citing the years-old Obama 57 states gaffe.
That time, she was talking about her 'party like it's 1773' gaffe about the revolution.
At some point of degree and a pattern, the politician moves from 'gaffe' to 'Quayle'.
Do her next 100 gaffes - next 1000 - all get to play the '57 states' card?
Let's be fair, these stories tend to get more attention when they fit a narrative - rightly or wrongly, sometimes they're manufactured and false (e.g., Gore the big liar).
When something fits that, people notice it. If Michelle Obama says *anything* about not loving her country, it'll get grabbed a lot more than without that story's history.
Palin has a pattern and a history after many gaffes that make it of more interests as she continues to make more, just as Dan Quayle did.
I used to make a comment like you did about Quayle, defending him that there was unfairness, until he made more and more that were bad enough to decide it was fair.
Palin has demonstrated such a contempt for a leader being informed, a contempt for voters with answers like her being qualified on foreign policy because she can see a Russian plane fly over, just proudly wearing the badge of ignorance, that it is fair to attack her for it IMO, rather than treat her as a likely presidential candidate, holding her to some standard, when polls show she is a leading contender and ignorance isn't as funny when the President does it.
There is a filtering process thousands of would-be nominees go through that informally sorts the wheat from the chaff - sometimes - and stories like this, when real, help.
(And stories that aren't real, like Al Gore saying he invented the internet, are not usually helpful to the truth or to our country).
I agree with you, though, gaffe stories like this are over-hyped and this is the least of the reason for concern with Palin.
One of the most famous, though, was when President Ford in a presidential debate called Poland a free country. You can't think he was that ignorant, but it hurt.