Casey is a symbol of the common person who faces overwhelming odds and refuses to give up. He is a small-town boy up against a big-city team, and he is determined to win. The poem glorifies Casey's courage and determination and celebrates the spirit of competition.
The poem is also about community spirit. The whole town is gathered together to support Casey, and they are all willing to believe that he can win. The poem shows how a sense of community can help people to overcome obstacles and achieve their goals.