Lots more potential Democrats, and maybe some others, yet to declare for the Democrat Primary. The fact that each will game whatever they can by timing of an announcement is to be expected.
That does not really matter for purposes of discussion about the pluses and minuses, if any, for any Candidate. We may as well begin with who the Media is presenting as leading, which are those who may be highest in the polls prior to a serious formal announcement.
Michelle Obama on a 'ticket' is certainly a possibility, and would contribute a large number of 'popular votes', which is what Democrats believe election of a President is all about... yes...?
Joe Biden so far is riding the media 'bumps' pretty well, and far better to get some things addressed early, which will surely need to be addressed later, if indeed he is to be the Nominee.
Both these two have great Name recognition. For Democrats, that may be all that is required, which works for each of these two, where getting 'deeper' may be not as positive. The competition will bring out any issues each will need to address, and with name recognition, there is no particular rush to announce.
Should we have a KB Poll to include all the potential and announced Primary names? May as well get the thought juices flowing...