This is a Kaiser Foundation tracking poll that asks voters what they care about:

And the follow up:

David Roberts from Grist notes that the environment is missing on this list. It seems that these issues line up pretty well with the issues that young people (18-30) care about. A Rock the Vote poll found that young people's top issues are: "the war in Iraq (28%), health care (22%), the economy (14%), and education (13%)."