Immunity doctrines, like qualified immunity, are not rooted in the text of Section 1983, but rather in common-law principles from 1871. The Supreme Court has largely presumed that the 42d Congress wanted these common law principles to apply. But the actual language that the 42d Congress used shows the opposite: It guaranteed that Section 1983 would hold state officials liable “notwithstanding" the common law.

The Institute for Justice filed an amicus brief (the first of its kind) explaining the effect of this "notwithstanding" clause—and urging the Supreme Court to apply it.