The Democrats would make the worst poker players. They have been dealt a series of winning hands against the Republicans that they have failed to capitalize upon. Winning hands that the Democrats end up losing their shirts, starting with the most recent, Jack Abramoff. The Republican Party were quick to associate Abramoff with the Democrats despite the fact that Abramoff never gave a dime to Democrats. Who actually could believe that the K-Street Project supported Democrats through campaign contributions is in need of assistance.
Then there was/is Abu Ghraib, Tom DeLay, Guantanamo Bay (GITMO), Scooter Libby (pdf), Harriet Miers nomination (and the party position that "We believe that every judicial nominee deserves an up-or-down vote." you said it Karl Rove), The Plame Affair, and Armstrong William (Bush's private propagandist).
Undoubtedly there are still more instances that I haven't mentioned. In the end, the Democrats are a party of Jackasses being led around.