Maybe I can simplify it a little bit.

Some of these people have spent their entire lives pursuing a philosophy (collectivism, and more specifically, Marxism/socialism) that was supposed to lead mankind into the light. I have talked to a few of these people who are onto the third generation of this kind of belief.

In point of fact, this philosophy, in actual practice, has destroyed nearly everything it has touched. Nations, lives, and wealth.

As time went on, and more of the truth became obvious, the disillusioned fell away. Some went on to other beliefs. Some just grew out of it, like we all do with some things. Some, in a "road to Damascus" conversion, became equally fervent opponents of collectivism. Over the 50s, 60s, and beyond, the process selected out all but the most rabid believers. It's not surprising to see a lot of them out there now, and they have little left but their anger.

The author did not say this, but it's my belief that the political victories of Reagan and Bush infuriated these people partially because it opened this wound.

What aggravates me is that many liberals try to pretend that anti-Americanism is playing no role at all in the current political upheaval. While it is certainly true that many, or even most, anti-war and anti-Bush people are not anti-American, it is equally true that some are, and some of these are in positions of influence.