1
general::
A feature or event that attracts a large audience. For example, This Italian tenor is always a good drawing card. Card in this idiom refers to a large poster containing an advertisement for something, often some sort of entertainment. [Late 1800s]
American Heritage Idioms
2
general::
Phrase(s): a drawing card
Fig. an attraction that helps bring patrons to a place of entertainment. • The comedian was a real drawing card at the night club.
McGrawhill's American Idioms And Phrasal Verbs