Paragraph four of Anna Quindlen "Quilt of a country" is mainly constructed with questions, and repeats the words "What is the point" at the beginning of each question.
She is trying to prove her point, that despite all of the cultures and ethnicities and different backgrounds that constitute the American people, it is not enough to disintegrate the nation, while other countries were torn apart by these differences.
A theme is best written as statement because a theme is main thing of a story, the author could also use a statement in a story to make it seem more alive or more real.