When you write something that promotes a particular cause, it is called PROPAGANDA.
Propaganda is defined as giving out <span>information, especially of a biased or misleading nature, and using it to </span>promote<span> a political cause or point of view. Most propaganda list down all the positive aspects of the cause and diminishes its negative aspects. There are those who write propaganda by citing all the negative aspects of the alternative, making sure that their specific cause is more attractive to their target audience.</span>
George looks out for lennie, and there like brothers