Answer:
He makes a logical argument based mostly on facts and statistics.
Step-by-step explanation:
Logos, which is the appeal to reason is a rhetorical appeal that makes references to verifiable facts, and statistics that support an argument. Logos applies logical reasoning and can not be easily refuted since it is based on facts.
Kennedy made use of this rhetorical appeal when he not just mentioned that immigrants were contributing to the professions and arts, but also making reference to a research work which had facts and figures to support the argument.