The AP reports that both Dean and Gephardt have pulled negative ads today. Here is a link:
http://www.guardian.co.uk/uslatest/story/0,1282,-3633229,00.html
Primary history is littered with examples of negative ads that have come back to haunt the candidate who chose to run them. It is instructive in this case that the two candidates who have fallen the furthest in polling are pulling their ads. From this, I think you can deduce two things:
*Both Dean and Gephardt have now realized that Iowa is no longer a 2 man race - hence what amounts to detente between the two campaigns. I'll go further; I am betting that each campaign now realizes they could finish third or fourth.
*The Democratic electorate simply wants more from their candidates than negative ads. My guess is that for Dean in particular, the negative ad came to be seen as a classic example of politics as usual - which is not good for someone whose core message is based on the need for new leadership.
A side note: in the past, most of the national news organizations polled extensively in Iowa and NH. In '96 for example, there were 5 tracking polls in the week before NH. This time, we have only one in Iowa and one in NH. In NH's case, I would argue the numbers are coming from one of the less reliable polling outfits around.