"Did you know that the White House drug test is multiple choice?"

This quote by Rush Limbaugh is an amusing way of mentioning the absurdity of drug testing in the White House. He is indicating that the drug test is not a major one, and that it is not a reliable way to determine if someone is using drugs. He is also implying that the White House is not taking the concern of drug use seriously. This quote is a method of highlighting the lack of seriousness with which the White House is dealing with the problem of substance abuse. It is likewise a way of poking fun at the White House and its policies. By using humor, Rush Limbaugh is able to make a point about the absence of severity with which the White House is dealing with the concern of substance abuse.