I agree up to a point, but I think you may be overcomplicating the explanation some. All the symptoms you describe — narcissism, inadequacy, dependency, senseless defiance — are hallmarks of immaturity. Children demonstrate all those same traits. So you are correct when you say that liberals don’t mature. Liberals are in essence overgrown children, and the government is their parent. It protects them and provides for them where they are too lazy or frightened to care for themselves. And being perpetual children, they can push all the hard decisions onto someone else while they skip about having random sex, getting stoned, and spending other peoples’ money.
I think narcissism is the hallmark of their leaders but not the followers. Many liberals actually hate themselves and why they really hate successful, hardworking people. That’s why I think it goes deeper than just immaturity. But immaturity is a big part that hampers their growth and their growth is stunted by feelings of inadequacy and the fear that comes with it. They can’t handle that fear that they don’t measure up. They feel that they should measure up automatically and naturally.