The lesson he drew from this insight is this: "..under a democracy, he [a "revolutionist"] is opposed by a horde so vast that it is a practical impossibility for him, with complex and expensive machinery, to reach and convince all its members, and even if he could reach them he would find most of them quite incapable of rising out of their accustomed grooves."
Mencken wrote this before the Palmer raids, to take one example.
You might think that the hysteria over the so-called "war on terrorism" is an example of this. When Edwards, a Democatic party candidate, tried to get the public to think of the so-called "war on terrorism" as merely a fabrication of the administration, the public simply could not deal with it. The public couldn't rise out of its accustomed groove, which the current administration foisted on the public. Standby for an orange alert right after Christmas, right before the Iowa caucus.
Here's an example about how the hysteria is playing out in the UK:
Here's what respected security expert Bruce Schneier says in his November 15, 2007 "Crypto-o-gram" newsletter:
"We've opened up a new front on the war on terror. It's an attack on the
unique, the unorthodox, the unexpected; it's a war on different. If you
act different, you might find yourself investigated, questioned, and
even arrested -- even if you did nothing wrong, and had no intention of
doing anything wrong. The problem is a combination of citizen informants
and a CYA attitude among police that results in a knee-jerk escalation
of reported threats." See