As pointed out by a friend:
This is a truly amazing, heartfelt public statement. This guy was clearly struggling with some deeply conflicting emotions in making the decision he made.
I recommend that anyone who’s still feeling that politics has degenerated into a series of cold, calculated power moves and perpetual campaigning (this can’t be a good move for his re-election outlook in conservative SD) should watch this clip and be reminded that it’s not all that way.