Some think it's a sickness, and some think it's a form of plain stupidity. Quite frankly it has something to do with those things. But, the extreme liberalism is a rebellion. It started in the early 70s around the Vietnamese war. Liberalism is basically a form of rebellion. The Vietnamese war up cry was around 40 years ago. Which means that that generation of "bitter teenagers" have grown up now and are infesting the United States political scene. In the 70s most older people had fairly conservative points of veiw. The children of that era (Who are now adults) detested authority. So they rebelled against their parents (conservatives). Due to the fact they were being drafted to a war. So naturally anything the parent (conservative) would say, they would disagree with. It carried all the way over to current politics. Liberalism is built off of being AGAINST instead of FOR. You see, it is always easier to detest something than come up with your own issues that you are FOR. The point is that liberalism is fueled off of opposing conservatism. They are a bunch of rebellious little kids that became adults and are involved in politics. That's my thesis on liberalism.
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PJC!