It's not that they are off-limits (though the Obama campaign has said they are), it's that they are immaterial. Palin has a wealth of scandals and problems in her past that have nothing to do with her knocked up daughter.
Her husband is fair game, you guys have been going after Michelle Obama since day one.
BTW, the Republicans DID run a negative ad on last Thursday.
I don't give a fig for your concern trolling of the Dem party's tactics. Palin brought this attention on herself when she decided to inject herself into the national media. You know as well as I do that the media are sharks and will go wherever there is blood; when the Rev. Wright deal came out, they replayed it constantly on TV and us on the left couldn't stop groaning about how unfair it was. Now, you get your turn to groan about how unfair it is.
I actually don't think that any liberal group has released an ad claiming that Palin is unfit to lead, based on any of her personal problems. And I doubt you can produce one. The base of the party, the online groups, are not under the control of the campaigns; you lump them all together when it is convenient for you to do so.
You ought to start facing the fact that the Hail Mary pass isn't working out. Palin was a mistake. Her political problems and un-vetted past are haunting her. The daughter thing, heck - that's nothing compared to the fact that her husband Todd was a member of a radical, secessionist group called the AIP from 1995-2002; that she tried to use her power as Governor inappropriately; that she ran her town's finances into the ground; that she was an earmark pig until it became unpopular; and that she's a liar about several instances in her life; that she had a business closed by the state for not filing the proper paperwork last year; that she instituted 'loyalty tests' on everyone in the town she was elected in, and tried to fire the librarian when she wouldn't ban books from the library; that she prays to god for oil and gas pipelines and thinks evolution should be taught in science class; that she doesn't understand the history of the pledge of allegiance; and I could go on. I'm sure by the end of the week we will know more.