I'm coining a new phrase today! The "Huckabee Index" is the number of any combination of superdelegates or convention/caucus delegates that the Obama campaign needs (or the Clinton campaign loses) to make it mathematically improbable for the Clinton campaign to win the nomination. Named in honor of the same Huckabee who stayed in the GOP primary race even past his point of mathematical improbability.

Today's Huckabee Index is 79 (or 24.9% of the remaining SDs)

Feel free to download the spreadsheet and play around with the polling figures. Here's the link:
http://www.box.net/shared/26wlqb9s8s

The spreadsheet accounts for delegates and superdelegates already earned, and projects probable delegate outcomes for upcoming contests based on polls, to arrive at a number of SDs that, if earned, would put the nomination out of reach for the other candidate if the rest of the contests go as polled. (You can change the superdelegate totals to whichever source you trust most ... I used NBC as my source because it lists the most reported superdelegates for both candidates.)

(disclaimer: I'm poking fun at Mike Huckabee, not Hillary Clinton)