If you took a netroots poll in 2002 (after Gore said he wasn't running, let's assume), you'd have seen Dean on top.  You'd probably have seen Clark make a small blip.  Gephardt would have shown up fairly low, Lieberman nowhere, and Kerry moderately strong.  That poll would have been highly relevant and informative to those who knew what it meant.  Public polls at the same time, of course, if they even asked about Dean or Clark, wouldn't have bothered to report the insignificant results for those two.  They all would have showed Lieberman with a commanding lead, and Kerry and Gephardt as the likely second tier.  Those polls meant nothing.