what do you mean "she also has made her children and family part of her platform"
She was introduced with McCain and her family was there, she spoke of her life that includes her family, other than that I am not sure what you mean?
Obama uses his wife and kids constantly in his "who I am and what I am about" but no one expects his kids should be attacked
I dont think her kids should be attacked. The announcement came because way back when she first had Trig, the far right in Alaska who hates her claimed she wasnt the real mother and it was Bristol's baby. It was though absurd here, and got picked up nationally. Which caused them to make the announcement and end that rumor that Trig in fact was not the child of Bristol and couldnt be, because in fact she was also pregnant at age 17.
She has always played her family in the forefront in Alaska. Todd is known as the Shadow Governor, she often has her children out in public and on the campaign trail. I am not saying the tactic is right, but both sides do it.