I know we like to think of 1992 as a masterful, against-the-odds victory for Clinton, but realistically the dam had been getting ready to break for a while.
I think what people say was surprising was that Clinton got nominated.
If you watch the Election Night returns on YouTube, you'll hear the commentators over and over again talk about how shocking the D wave was that night after R's were doing so well a year ago. This stood in stark contrast to 2008, where it seemed like the media was just going through the motions to get to the big moment at 11:00.