I think it would be easy to come up with a dozen of examples of worst Democratic behavior. Shoot, Barney Frank had a gay escort service being run out of his apartment by his 'partner'.
I agree with you that there certainly are a lot of examples of Democratic hypocrisy from which to choose. I do think, though, that the Mel Reynolds pardon is the most unanswerable by the Democrats for two reasons: 1. it is recent, and the pardon was granted by the man who is, arguably, the leader of their party (and who they rhapsodize about to this day); and 2. you can't get off with even the most ridiculous strained factual dodges to avoid the issue, like claiming Barney Frank "didn't know" about the escort service. Mel Reynolds was convicted criminally; he had a full factual inquiry, including the protections of the criminal justice system and the beyond a reasonable doubt standard. His conversations were on tape. There is no factual question as to what he did, nor as to what Bill Clinton did. I think you can clear away a lot of the obfuscation that the Dems love to use and get down to essentials pretty quickly on the Reynolds matter.