There doesn't seem to be a great match.
McCaskill may have bad blood. The party prefers Hassan run for Senate. Gilibrand has unique legal issues as a fellow New Yorker (Hillary might be able to change her state affiliation, although that's going to come with legal challenges and media scrutiny.)
Klobuchar's a generic Senator, and not really from a swing state (if Minnesota is competitive, the GE is lost.)
Warren lacks demographic appeal (New England is not a politically useful region), doesn't want to be in national office, and wasn't that effective a campaigner, although her reputation as a policy leader is likely to mean the top story that two women are on the ticket.
I highly doubt she would select Claire, seeing as how Claire said she didn't want to be stuck on an elevator with Hillary.
I like Jennifer Granholm, but she has the Ted Cruz Canadian conundrum.
Granholm was born in Canada to Canadian parents, so I don't believe that she's a natural-born citizen.
