The worst sin of all ("sin" means "to miss the mark" and comes from archery) is Pride, or what the Greeks called Hubris. It is the basis of all the rest. The second worst sin is envy.
Leftism, which I don't believe in at all, is based first on Hubris, and secondly on envy.
Those two sins are why leftists think they are intellectually and morally superior to everyone, and why they are levelers - to get rid of envy (of course, as long as they rule the inferior unwashed masses).
It is an impossibility for anyone to be smart enough, and moral enough, to run the lives of hundreds of millions of people. It's why I believe in the smallest possible government, liberty and the free market.
Because I know I'm not smart enough to run someone else's life. Which makes me the Anti-Leftist.