Peter made a gut decision that he didn't want the woman who fired his wife to be his state supreme court nominee. In doing so, he just made his wife an enemy she really didn't need, and ensured continuity of leadership at the top of Lockhart/Gardner.
This promises to be one hell of a ride.
The question is whether they are better off with Diane as a supreme court judge or still with Lockhart/Gardner. Peter just is looking into other nominees - I don't think he hasn't made a final decision yet.