Personally, I think Rich suffers from delusions of grandeur in a clinical sense. I think he truly is mystified as to why we don't see things his way and is literally incapable of comprehending the concept that he might possibly be incorrect.
This manifests as what others observe to be sarcasm, side-stepping, grand generalizations, hypocrisy, etc., when in his mind it is a perfectly logical and reasonable progression of thought. For example, no matter how many insults he slings at someone (either directly or by implication, the latter being his overwhelming preference) he honestly believes he is wronged when somone insults him. This pattern (eg., engaging in a certain negative behavior, complaining when another person behaives the same way, and finally failing to understand how the two behaviors are equivalent) repeats itself over and over in a near-Shakespearean comedy of errors.
That's why I stopped when I caught myself responding to the problems in Rich's post. He's not stubborn, or a jerk, or closed-minded, or uncaring; he just doesn't understand. You may as well try to explain the difference between red and blue to a person who was born blind.
Colin is a completely different story. I'm pretty sure he just feels constantly bombarded by crap that originates in the U.S., especially since Blair is basically an amplifier/repeater for it. Therefore, it helps him feel better to fire right back.