A second Democrat, state Senator David Gottesman, said that he is no longer interested in challenging Republican US Senator John E. Sununu in 2008.
Earlier this week, Stonyfield Yogurt CEO Gary Hirshberg said he, too, would not run.
The race is considered one of three in 2008 that could decide which party controls the Senate, which Democrats currently control by one seat.
So far, two Democrats -- Portsmouth Mayor Steve Marchand and former Congressional candidate Katrina Swett -- have filed to run against Sununu. Former astronaut and Dartmouth Medical School professor Jay Buckey, also a Democrat, has formed an exploratory committee.