Part of William Safire's column on words in the New York Times, 1
Oct. 2000:

        Package Deal
              In the Left Coast [Los Angeles] convention speech introducing
himself to the
          nation, Senator Joseph Lieberman said: "My dad lived in an
orphanage
          when he was a child. He went to work in a bakery truck and then
owned
          a package store in Stamford, Conn."
              The week before, however, in a speech to the A.F.L.-C.I.O.
          convention in Hartford, Lieberman used the phrase "liquor store".
          Crawford Lincoln of Brimfield, Mass., asks, "Was this a gentler
          locution to soften the image of his family's business for a
national
          audience?"
              I'd say yes, and thereby hangs a euphemism. A "package store"
          is a store, not a bar, where liquor is sold by the bottle and not
          by the drink and where the contents of the "package" is consumed
off
          premises.
              In 1880, Bradstreet's weekly reported active trade in "package
          houses". In 1890, The London Daily News reported that "Judge
Foster
          recently decided that liquor could only be sold in 'original
          packages,' which is construed as meaning one or more bottles of
beer
          or whisky. The merchants . . . are not allowed to sell beer or
whisky
          by the glass."
              Our earliest evidence for the phrase "package store", I am
          informed by Joanne Despres at Merriam-Webster, "is an entry in the
          1918 Addenda to the New International Dictionary (originally
published
          in 1909), where it is labeled 'cant, U.S."' (Cant means
          "jargon," and business euphemisms fall into that category.)
              Let's face it: what the seller is selling is not a package but
what
          is contained in the package, which is liquor. Why the
squeamishness
          about that word? After Prohibition was repealed in 1933, state
          legislatures had the opportunity to license booze shops and
saloons
          but did not want to upset the many "drys." That led to the
linguistic
          prettification of saloons as "taverns" and of shops purveying the
          mother's milk of John Barleycorn as "package stores".
              Maybe the senator uses the terms interchangeably. But I have a
          hunch that some politically sensitive soul remembered that "drys"
          still exist and vote and changed the candidate for vice
president's
          word from "liquor" to "package".  It shows a
          sandpapered-fingertip sensitivity to the shades of meaning of
words.