As for construction, I read (3) as equating the circumstances in (1)(B)--"insurrection, domestic violence, unlawful combination, or conspiracy"--with denial of equal protection, under the condition that the circumstances in (2) have emerged. It doesn't mean (2)(A) is automatically satisfied under a (1)(B) emergency situation. The implication is that the circumstances in (1)(A)--those resulting from "a natural disaster, epidemic, or other serious public health emergency, terrorist attack or incident, or other condition in any State or possession of the United States..."--are *not* to be so deemed. Compared with the 1871 statute this makes sense, because the new language (for better or worse) preserves the original circumstances under which the State's failure or inability to protect is deemed a denial of equal protection, but doesn't extend denial to include those new circumstances--natural disasters and such--that did not appear in the early statute.This does make sense. So I guess we can breath easier that the new statute doesn't in effect authorize the use of the federal military against all conspiracies, only those that hinder the execution of state or federal law.
This still leaves the problem with the new natural disaster provision, in light of Morrison. (For the record, I think that DeShaney and Morrison were both wrongly decided -- that plus about five bucks will buy you a vente latte somewhere.) The bottom line is that the statute seems to do hardly anything to deal with the issue of catastrophic collapse of local law enforcement capacity.