Over the last 49 years, a lot of things have changed on the north side of the White House compound. Outside the grounds, the street is studded with car-stopping bollards, the result of 1980s fears about truck bombs. Pennsylvania Avenue — once a busy, honking commuter route — is quiet and empty, closed after the 1995 Oklahoma City bombing. Inside, special teams were deployed to send attack dogs after intruders who made it to the lawn.
What hasn't changed is the fence between them.
That may be about to change. Friday's stunning intrusion at the White House — in which a Texas man made it over the fence, across the lawn and through the mansion's unlocked door — revealed key failings in the Secret Service's second line of defense.