I would think it would be too late for Caroline Kennedy to establish Massachusettes residency. She was born in NYC, moved back there with her mom a week after her father was assassinated, and has pretty much lived here her entire life.
My bad: Jackie kept the kids in Georgetown for a while after dad died, but officially moved to NYC in the spring after their townhouse became a popular tourist destination.
If you will remember, Caroline’s brief candidacy in NY collapsed into a bowl of quivering stupidity, from which she will never recover.