For those who talk about a Clinton-Obama ticket or an Obama-Clinton ticket: no. I don't want it. Having Obama as Clinton's VP running-mate would not get me to vote for her. Having Clinton as Obama's running mate would not stop me from voting for him, but I would still be very uncomfortable with someone as unscrupulous as Hillary Clinton one heartbeat away from the most powerful office in the land.
Fortunately, Roland Martin at CNN has made very good arguments indeed why neither matchup will ever happen.
(1) In a Clinton-Obama matchup, Obama would overshadow Clinton, which would be intolerable to Bill and Hillary.
(2) In an Obama-Clinton matchup, Obama loses all his advantages of "new politics," lack of baggage, etc. making Hillary a hindrance, not a help, in the general election.
(3) There's too much bad blood between the two for them to be on the same ticket.
(4) Clinton absolutely will not subordinate to Obama, or anybody.
(5) Whoever Clinton might name as VP, her husband would actually wield the power. Obama as VP would be utterly powerless- shut out like LBJ was by Bobby Kennedy.
They're all excellent arguments. Obama will want someone with a reputation for building bridges across the aisle, and Clinton will want someone firmly under her thumb. Neither fits the other's job description for VP.
So it won't happen, for good or ill.