What is the significance of the poem?

Holden tells Phoebe that when he had to think of something that he would like to do for the rest of his life, he thought of the poem. Holden told Phoebe, "What I have to do, I have to catch everybody if they start to go over the cliff- I mean if they're running and they don't look where they're going I have to come out of somewhere and catch them."(Salinger, 173). Holden talks about children going over the cliff and he has to protect them. The cliff may represent loss of innocence, or becoming a phony, and Holden must catch them, or stop them from losing their innocence and becoming phony. The poem represents everything Holden stands for, he wants to protect the innocent and stop them from becoming everything he hates.