" ... Since the Greek phrase includes an article, some critics have argued that the phrase the hoi polloi is redundant. But phrases borrowed from other languages are often reanalyzed in English as single words. For example, a number of Arabic noun phrases were borrowed into English as simple nouns. The Arabic element al- means "the," and appears in English nouns such as alcohol and alchemy. Thus, since no one would consider a phrase such as "the alcohol" to be redundant, criticizing the hoi polloi on similar grounds seems pedantic."

From here.