it has any logical right to be 구문 질문

There are those who say they should be free, but in spite of freedom they should be always good. This last party is larger than it has any logical right to be.
여기서 they는 children을 가리키는 것으로 보입니다.
마지막 문장의 larger than it has any logical right to be는 어떤 구문인가요?
party를 it has any logical right to be와 비교하는 구조가 궁금합니다.