Paul Krugman, who I often believe is exceptionally tone-deaf regarding politics (but usually right on the merits of policy), is, IMHO, absolutely right here:
First, Pelosi has by all accounts been an extremely effective leader. She made health care happen, when it was taken for lost; she has shown an amazing ability to herd cats, and from what I hear her caucus appreciates her talents. If the economic policies fell short, if the White House did a terrible job of messaging, well, that’s not her fault.
Second, and following from this: getting rid of Nancy Pelosi now would serve no purpose other than to throw an alleged wild liberal to the conservative wolves. It would, in effect, be admitting that America won’t accept anything that looks like a progressive policy; it would basically mean conceding that the Republicans were right.
So the Pelosi issue is about whether the Democrats will fall back into their good old cringe.
Democrats would be fools to let the GOP have another scalp. Period.