Harold Myerson of the Washington Post has a very interesting column about the appearance of the three top Democratic presidential candidates at the recent DNC meeting. He writes that each of them displayed strengths and weaknesses.
Edwards strength was his ability to make the case on how Bush's economic policies are hurting Americans, especially Americans in union jobs. His weakness was that he didn't outline proposals to reach the unorganized part of the middle class, people who work at keyboards, not machines.
Clinton's strength was her ability to state how devastating Bush's policies have been to the entire middle class. Her weakness was that her policy proposals seem incremental and not enough to take on the wide scope of the problems she accurately identifies.
Obama's strength was his ability to speak to the destruction of faith and hope in government that conservative policies have brought about, but his weakness was that he didn't have policy proposals to match his language
The entire column can be read by clicking on the link in this entry's title.