What is the main idea of magic island? by Cathy Song

Although individual circumstances differ, immigrants share the experience of adapting to a new and unfamiliar environment. They must learn new behaviors and languages while keeping alive the traditions and values of their original cultures. Poet Cathy Song was born in Honolulu in 1955. Her grandfather came to Hawaii from China; her grandmother arrived from Korea in an arranged marriage. Their experiences inform many of Song's poems.

The main idea is the immigrant's feelings.

Explanation:

Song's poem is about an immigrant family that is in a very happy place, meaning that they are comfortable and life seems beautiful and easy, free of worries. Nevertheless, the father is concerning about the whole situation, he, as the family cornerstone, is worried about anything that could go wrong again. There are not specified the circumstances of their immigration, but this action implies unfavorable circumstances. "They keep expecting rain" means that no matter how good things are going, they will always have this fear of not feeling like they belong in a place.