Well it's out of line if it was directly targeted at Palin's child.
Yes and no. If you're a public figure, you're a legitimate object for general satire. But yeah, by clearly making the identification with Palin, they left her with pretty much no choice but to respond, given what she's doing right now.
Last night as I lay in bed, looking up at the stars, I thought, “Where the hell is my ceiling?"