Why are most commenters in online newspaper forums so nasty, self-important and intolerant?

I am trying very hard to avoid reading the comments in my local newspaper's online forum. You may recall I earlier described the Jefferson City News-Tribune as a fascist rag sheet and that still applies. The same group of posters still lie in wait for anyone whose comment may reveal him or her to be liberal, Democratic, left-leaning or even a moderate Republican--then they pounce and denounce the commenter as a socialist, communist, leftist, pinko or traitor, and those are some of the nicer accusations. Here are some examples from a quick scan of tonight's entries.
* Commenting on a story about some legislators introducing yet another school prayer amendment, a frequent (and ignorant) poster named Boscoe wrote, "I say BRAVO to the legislators! If the heathens don't like it, they can go live somewhere else. Our country started just fine without the Muslims, so we won't miss any of 'em if they leave." Another local lunatic, a very angry and pompous wingnut named Byron W. wrote, "BRAVO!!!!!! It is time to take a stand for Christianity and a stand against secularism. "(Actually I was surprised at the number of rational opinions among the Yay for Christians comments.)

* Here are some comments in a story about those goofy tea parties last week: "The LEFT wing fringe that is now in the Whitehouse is squirming and are worried, don't be fooled by their lies." Here's nutcase Boscoe again: "Yes, the Repubs lack a leader, but that is also true of the Democrats. All they have for leaders right now is a flash-in-the-pan Rock Star, a crazy old hag in the Senate, and the old guy who has all these mysterious deaths and misadventures when they ride in his car. Oh, I forgot about the finger-pointing adulterer and his power-hungry manic wife."And my favorite from the whole thread: "Remember these two, they are trying to create diversions: JANEANE GAROFALO, KEITH OLBERMANN." I was quite amazed by this, that some wingnut even knew about Janeane and Keith. What followed were several comments about her ethnic heritage somehow contributing to her so-called radicalism.

* Byron checks in on health care: " National health care? Just another nail in the coffin of the USA." I wonder why he is such an angry, unhappy grump--oh I remember now--OBAMA WON.

I typically go a few days without reading the comments. But then I'm overcome by an urge to check out the latest ones and get horrified and disgusted and depressed all over again, and swear off the online forum forever, again. I think this affliction must be similar to my Sarah Palin sickness--I can't get enough of that pathetic, deluded woman. Come to think of it, a lot of the News-Tribune posters are big fans of hers. There used to be a lot of PALIN 2012 sign-offs, but not so much lately.

Occasionally I actually post something myself--typically an ultra-liberal, Obama-loving observation designed to agitate the Boscoes and Byrons out there. When they call me a Nazi I know I've succeeded.

The truly remarkable thing I've discovered, however, is that hateful, depraved, frustrated commenters are universal. Visit any online forum at any newspaper in the US and you will find them spewing their ignorance and anger in their local market. Here's a choice nugget from tonight's St. Louis Post-Dispatch forum, regarding the sale of props used in the George Clooney movie that recently wrapped up shooting there: "I guess since his movies are flops, and his totally liberal policies and meddling are coming back to haunt him, his only way to make money is a traveling gift shop."

Insane commenters make up the majority of posters no matter where you find them. I think that's because the forums give them an outlet for their sense of helplessness, a place where they can lash out against "us" without repercussions.

What do you think?