The lack of organization–even with the efforts, only about 32,000 people voted in the primary—a winning race will take 140-160,000 votes. Ultimately Democrats don’t have the base that Republicans do—Roskam received 44,000 votes in DuPage alone and another 5,000 in Cook (Dems cast more ballots in Cook, but hard to say if that had something to do wth the Claypool race or not).
While Democrats got 47 percent of the Presidential vote in 2004 in that District, there is still an organizational problem and the organizing for this race isn’t going to fix that problem.
The good news for Democrats is that the Presidential vote was about the same as nationally and Bush’s numbers are in the tank. Even then, Democrats have to reach those voters and find a way to ensure they get to the polls. Being a midterm, turnout will be slightly lower probably giving another slight advantage to Roskam.
Expect each side to exploit every wedge issue at their disposal and do it in the most expensive manner possible.