1) Kentucky has a closed GOP primary. Conservatives were willing to support a Tea Party candidate--but we don't yet know if indies and Dems will be, here or elsewhere.
2) Kentucky's GOP is split into factions. Last night's results showed only that the Paul/Bunning wing was stronger than the McConnell/
3) Paul's celebrity dad brought him money, volunteers, name recognition, and media attention, particularly on Fox News. What other Tea Party candidate can match that?
4) It was well known among Kentucky GOPers that Trey Grayson was a Bill Clinton supporter and volunteer, and a member of the Harvard College Democrats.
5) The Grayson family were notable Democratic fundraisers until they sensed the climate shifting in northern Kentucky, and the whole state shifting toward the GOP. They're not beloved.
6) Grayson's political maneuvering backfired disastrously. He was a Bunning protege, then stabbed his patron in the back by forming an exploratory committee before Bunning dropped out. Bunning then endorsed Paul. Nobody likes a man in a hurry.
UPDATE: Bonus 7) Democratic turnout was much, MUCH higher than Republican turnout.
This article available online at:
http://www.theatlantic.com/politics/archive/2010/05/6-reasons-why-rand-pauls-win-doesnt-herald-a-tea-party-tidal-wave-updated/56942/