How are the 4 I mentioned a loss to the GOP? They aren’t. Neither would sh*t for brains losing.
Those 4 are merely liberal republicans holding (or were, or vying for) contestable seats where we can do better, seats that are in play in elections, the Kennedy seat is not.
Brown winning that permanently Democrat seat was a fluke and a lucky break, either he stays in it or it reverts back to it's normal state, radically leftist.
The permanent Ted Kennedy seat is totally different than the 4 you mentioned, don't look a gift horse in the mouth.