1
general::
Phrase(s): drive something home [and] drive something home (to someone)
Fig. to emphasize an important point about something (to someone). • The teacher repeated the point three times just to drive it home. • I hope this really drives the importance of safety home to you. • The accident drove home the importance of wearing seatbelts to everyone concerned.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Make clearly understood, make a point, as in The network news programs drive home the fact that violence is part of urban life. This expression uses the verb drive in the sense of "force by a blow or thrust" (as in driving a nail). Samuel Hieron used it in Works (1607): "That I may . . . drive home the nail of this exhortation even to the head."
American Heritage Idioms