If you can forget for a moment the utter pointlessness of the story, I think there is a moral here.
Obviously, it should have been titled "liberal encounters patriot on bus." I think the moral lies in the construction of the story rather than the story line. I noticed the liberal was typical until he began to talk with the patriot. At the end the liberal essentially asks whether or not he should be more like the patriot by adopting the patriot's 'sth' in his own sentence. The moral of the story would be that patriots are making a difference with every encounter.
We make a difference by just being there...