She hasn't left the fold, and won't. They've given her a pass, I'm sure, which they're always willing to do for any given loyal lackey from time to time, as long as there are enough aisle-crossers left to give 'em a majority.
Hillary is such a valuable asset that they don't want her to have to take any unnecessary heat until she's safely ensconced in her husband's former chair. -- Well, maybe she'll use a different chair.