For those who don't know, the University of Iowa B. School has managed an on-line electronic futures market for some time—a market that has proven extremely reliable in predicting future outcomes. (Learn more about the IEM here.)
Here's the latest Daily Prices Graph for the Democratic nomination. The leading candidate, “ROF” represents any candidate OTHER than Gephardt, Kerry, Lieberman, or H. Clinton (ROF=Rest Of Field). Notice that Gephardt's price tends to fluctuate in tandem with interest in the rest of the field (ROF).
There is a market for the General Election as well, and here's its most recent price chart. Note that there are a variety of contracts: those for a particular Dem candidate (KERR represents a Kerry victory), and those for Bush winning over a Dem candidate (BU|GEPH represents a Bush victory over Gephardt). Also note that ODEM represents any other Dem candidate, and that current pricing reflects a near even heat between ODEM and BU|ODEM.