Coates points me to this post by Dana Goldstein:
Sebelius, of course, would be the bold, unconventional choice — very Obama. But by choosing a female running mate, Obama would, unfortunately, thrust the Hillary die-hards and their ever-more marginal discontentment back into the spotlight. That said, anyone who believes that only Hillary Clinton deserves to be the first female president or vice president doesn’t deserve the designation "feminist." So I’d relish watching the reactions to a Sebelius nod, not only because such a choice would double down on Obama’s most effective message — "change" — but because it would reveal exactly which Clinton boosters are ready to widen the lens and enthusiastically support women’s leadership as such.