Yes, I've been on a few days, made several posts already but recently wrote much of what is posted below and thought it was appropriate to edit a bit and put it here so y'all know where I was coming from.
Not bragging, but my Bachelor degree was in Behavioral Psychology, late 1970s. Although mine was a military aviation career, I always maintained an interest in that field of study. Yes, I was able to apply it in my career and life, but I never did actual work (research) in the field.
I've been online since 1986 when there were BBS's using 300 baud modems...you could actually see the words type across the screen as the other person responded. In those days we'd meet once a quarter, drink beer and share software on 5.25" discs, later 3.5" discs. I wasn't a member of political forums until around 2008. Since then, and getting to the point, I've noticed that there seems to be more mentally ill people online than in real life (IRL).
In some ways I think it might not be mental illness but an example of "a drunk man's words are a sober man's thoughts". The mask of anonymity given by online forums allows people to say their true thoughts without fear of recrimination. That point aside, and I do believe it's the most common reason some people are bigoted, biased assholes regardless of political affiliation, my observations over the years tell me that there are, indeed, a higher number of truly mentally ill people online.
Here's my theory on why: anyone with access to the Internet can log on to a forum. People shut in behind locked doors of a private mental facility, retirement home or group home can access computers. Even if a person, and notice there's lot of elderly people online, is living with their adult child, due to health, they can't get out much and the Internet is their access to the world. Their primary access. Being in pain, they express that pain in posts to virtual others, "people" they think are as real as the ones they kill in video games or beat in Farmville, whatever.
Last point: people who are angry and/or hateful are often in pain. Most people are good. A happy person is often good. An unhappy person often is not good. These are generalities, so individuals vary, but it's not that hard to look at others on this forum and form a general opinion on their behavior. This isn't an excuse for these hateful people, but an attempt to understand them and put their behavior in perspective. Seriously: should we hate a person who is mentally deranged or just pity them, lock them up and move on?