I wholeheartedly disagree with Rick Warren when he says that we need both 'wings' to fly, both right and left.
As this picture shows, two people well-balanced and peaceful. Who needs a worthless left-wing? When you only have a right wing, you go right- the only direction one really needs in life. You will eventually get to those left-leaning things that are worthless after experiencing all things great and good on the right! Furthermore, when you get to those 'lefty items' you will realize that those things are now obsolete and beneath you and can leave it for the '90%ers'