It grew strength from the young people who rejected the myth of their generation's apathy; who left their homes and their families for jobs that offered little pay and less sleep; it grew strength from the not-so-young people who braved the bitter cold and scorching heat to knock on the doors of perfect strangers
Obama uses pathos by talking about his people and how their strength through their trials is what grew victory
For that is the true genius of America - that America can change. Our union can be perfected. And what we have already achieved gives us hope for what we can and must achieve tomorrow.
Obama uses Pathos by being honest and using logic to explain that America can change and that our achievements have obviously made us one step closer.
As Lincoln said to a nation far more divided than ours: "We are not enemies, but friends… though passion may have strained it must not break our bonds of affection."
Obama used Lincoln in his speech to add a trustworthy individual so that we may believe that what he is saying is true.