Abstract: The defense of qualified immunity enables government officials to defend against constitutional claims on the ground that the right they violated was not “clearly established” and therefore a reasonable officer would not have known that his conduct violated the law. It’s an oft-asserted and powerful defense. And at the Supreme Court, it’s the rationale for a steady string of summary reversals, including yesterday’s decision in Taylor v. Barkes. It’s worth asking what function these reversals serve.