Does a plaintiff have to find a case with identical facts in order to survive a defense of qualified immunity?

Of course, it is true (as far as it goes) that a plaintiff need not find a case with identical facts in order to survive a defense of qualified immunity; obviously, one can imagine a situation where the officials' conduct is so egregious that no one would defend it, even if there were no prior holding directly on point. See, e.g., Hope v. Pelzer, 536 U.S. 730, 741, 122 S.Ct. 2508, 153 L.Ed.2d 666 (2002) ([A] general constitutional rule already identified in the decisional law may apply with obvious clarity to the specific conduct in question, even though the very action in question has [not] previously been held unlawful. (internal quotation marks omitted)). But it should be equally obvious that the farther afield existing precedent lies from the case under review, the more likely it will be that the officials' acts will fall within that vast zone of conduct that is perhaps regrettable but is at least arguably constitutional. So long as even that much can be said for the officials, they are entitled to qualified immunity.