1) Liberals believe they can change human nature. Sure, human beings can be shaped and molded to a certain extent. Any parent who has spanked a child can tell you that. However, most people care more about what they're having for lunch today than an earthquake that kills ten thousand people on the other side of the world. We're just built that way and no amount of sensitivity training, preschool classes, or Michael Moore documentaries is going to "fix" it.
2) Liberals believe we can talk everything out with our enemies. One of the weirder quirks of liberalism is their belief that many of our bitterest enemies have rational reasons for disliking us and that can easily be talked away if they realize we're good people. Hence, the common liberal refrain of, "Why do they hate us?" The reason this is a particularly odd belief is that liberals don't even believe this about conservatives in the United States. The average liberal thinks that if we're nice enough, we can reach an understanding with Hugo Chavez or Mahmoud Ahmadinejad, but Rush Limbaugh and Glenn Beck can't be reasoned with.
3) Liberals don't have enough respect for our culture and traditions: To liberals, our cultural, economic, and political norms were formed by backwards troglodytes making arbitrary decisions based on superstition and racism. Unfortunately for them, as a general rule, that's not so and proceeding as if it is, will often lead to exactly the same difficulties that our ancestors already dealt with in times past. No matter how smart we are, as Thomas Sowell would say, our wisdom is often no match for the "distilled experience of millions who faced similar human vicissitudes before." Truly wise people are aware that there is a great deal that they do not know.
4) Liberalism is a fundamentally immoral political philosophy. Ironically, given all their talk about "shades of gray," liberals have a very Manichean view of the world. They consider their fellow travelers to be on the side of the angels, while the people who disagree with them are treated as evil. This leads to an "anything goes" mentality when dealing with their foes: ignoring the law via a "living constitution," politically based prosecutions, shouting down opposing speakers, and treating lying about their agenda or opponents to be moral. On the other hand, liberals will support other libs, no matter how corrupt, sleazy, or vile they are as long as they're politically useful to the left. See Ted Kennedy, Barney Frank, John Murtha, and Robert Byrd for examples of that. In other words, as Margaret Thatcher has said of the Left, "For them, the end always seems to justify the means."
5) Liberals believe merely being liberal makes them good people. Liberals who're obsessed with money think they're compassionate because they give away other people's tax dollars. They believe they care more about the earth than other people, even as they fly around in private jets, because they babble on about global warming. They can be dumb as a rock, but believe they're smarter than most other people because they're liberals. In other words, in the minds of most liberals, liberalism is an all-purpose substitute for actual virtue instead of just another political philosophy.
6) Liberals have too much faith in government. Even most liberals would admit that government regularly fails the people. If you don't believe that, just ask them about the Bush Administration and they'll give you an earful. However, liberals tend to believe that with the right person in charge, government won't be so slow, stupid, inefficient, and badly run. Human history proves that they're wrong about that.
7) Liberals have minimal interest in whether the programs they support work or not. To most liberals, whether a government program betters people's lives is completely irrelevant to whether they'll support it. A program that doesn't work and costs billions, but sounds compassionate and helps Democrats politically is a huge success in the eyes of the Left. Once you understand that liberals think this way, their baffling support for programs that make no "common sense" is much easier to understand.