The rulers will often act in secret; for reasons of "national security," the people will not be permitted to know what goes on in their name. Actions once unthinkable will be accepted as routine: government by executive fiat, the murder of "enemies" selected by the leader, undeclared war, torture, mass detentions without charge, the looting of the national treasury, the creation of huge new "security structures" targeted at the populace. In time, this will seem "normal," as the chill of autumn feels normal when summer is gone.
(yes, 1.0 and Graham both blogged this, but it's well worth a read)