John Hawkins lists six, and you could expand or contract this list if you chose. So as not to steal his thunder, I’m just going to highlight and comment on two of them.
1) You really didn’t learn everything you needed to know in kindergarten: Argue with leftists and you soon realize that they have neither learned to think much beyond simplistic slogans, nor have they matured beyond the egoism of a five-year old child. “Torture is wrong!” they proclaim. “But is pouring water on a terrorist’s nose really torture?” you may ask. “And is there a moral difference between inflicting pain on a helpless person just for the sake of inflicting pain, and inflicting pain for the purpose of illiciting information that may save innocent lives?” At which point, they will ask for their milk and a rug to lie down on.
“Trust yourself. You know more than you think you do.” — Benjamin Spock: The left has been raised on self-esteem and Hollywood movies. In the movies, the person who uses reason, and deliberation is either evil or wrong, and the person who acts on his emotions is always right. The left takes this to mean that only emotions are true and can be trusted. Obama and Carrie Prejean have exactly the same position on gay marriage, but Obama is right because they love him, and Prejean is wrong because they hate her. That’s what passes for logic on the left.
There are four more, but I’m not gonna spoil it.