Who will be running in the next Democratic presidential primary?

There are a fair number of Republicans who have been suggested as possible candidates. Regardless of your political affiliation, I think you would agree that overall they are more qualified than the jokers who ran in the last Republican presidential primary.

Other than Hillary Clinton, who so far has said she is not running, there do not seem to be any Democrats under consideration. Biden? Kerry? I suppose they are possibilities. It would be nice to see some fresh blood, someone who has not run previously.