Bill isn't allowed because he couldn't take over should something happen to Obama.
Strickland is a viable choice as the governor of Ohio (a state that Hillary won)
Richardson may bring more Hispanics on board, but that could backfire as racist because there's no whites on the ticket. I think this would be a bad choice.
I keep mentioning Jay Rockefeller, but nobody else seems to agree with me. He is a ranking committee member of the Armed Forces Committee and would have a lot of insight into foreign affairs where Obama's presumed weakness is.
He is also a loved Senator for West Virginia, another state that Hillary won largely, and this could help him. I'm not sure if Rockefeller is seeking the nomination, though.
Maybe Secretary of State at least?
Source(s):
Why didn't Rockefeller run?