Picard: You know, the last time Beverly took over Starfleet Medical, I was given a stubborn, acerbic, cantankerous replacement who I firmly believed was sent specifically to drive me mad. And I'd love to have her back, if she's interested.
Moral Event Horizon: Prime Minister Kinchawn crosses it rather early, after he uses his illegally-acquired weapons (see: Government Conspiracy, above) to shoot down 10 Klingon ships in orbit of Tezwa, killing 6,000 warriors. If this didn't represent his crossing the line, his casual willingness to see millions of Tezwans killed in a Klingon counterstrike, including his own family, certainly does. What makes it worse is his apparent self-image as a Well-Intentioned Extremist, when he's really totally Drunk with Power. He sees his own children's death as merely a means to acquire more sympathy and thus more support and power, and seems to truly believe this is somehow reasonable.