Talking about them is not "targetting" them. The commercial indicates that these children are afforded certain protections. Protections that various politicians and opportunists are trying to deny to my children, by virtue of my lowly status as a mere commoner/peasant. To say that the Obama girls are being "targetted" is nothing more than an attempt to appeal to emotion without any intellectual integrity whatsoever.
Nobody is holding those children up to ridicule. Nobody wants to deny them the protection they're entitled to. People are merely asking, "Hey, why can't I protect my kids the same way those kids are protected". That's not an unreasonable question by my reckoning.
Now, if you want to read about politicians' whose children actually became "targets", try googling Sarah Palin.