This article was featured in the One Story to Read Today newsletter. Sign up for it here. On one level, the system worked. The perimeter held. A would-be assassin was tackled in the hallway outside the White House Correspondents’ Association’s annual dinner. The one bullet that found a human target—a U.S. Secret Service agent—was halted, in part, by the officer’s phone and bulletproof vest, according to a law-enforcement summary report that we reviewed. A counterassault team promptly swarmed the stage with assault rifles and night-vision equipment in case the lights were cut. The government’s top leaders—president, vice president, Cabinet officials, speaker of the House—were ushered to secure locations in a matter of minutes. No one died in the attack. But the collective sigh of relief and rounds of “I am fine” text messages last night belied a heaviness that administration officials and other dinner attendees were still processing this morning, even as Sunday brunches proceeded apace, albeit with more security and a newly somber sheen. This attack was different from the two prior assassination attempts …