>>a. some cathartic event like Watergate or
>>b. exceptional leadership - we haven't seen that since FDR- or
>>c. both.

There's so much loud shrieking about Obama causing drought, epidemics and plagues of locusts that Watergate wouldn't have much of an impact today IMHO. More shrieking erupts and people twitter in to vent some fury, but then have to get back to work. As for leadership- bureaucracies shun chaotic visionaries and steadily convert themselves into grey plodding artifices unless there is a periodic severe jolt. Churchill experienced that, banished to the wilderness for his impetuosity until another World War made his attributes suddenly valuable again. What sort of jolt can we hope for today? At this point, IMHO the US public's appetite for a World War is even lower than it was the last two times. Hence the PP (Pitchfork Pessimism.)