Describe the similarities and differences that you see in campain commercials from 1950s to 2010. Although discussing issues of style (length, etc.

Describe the similarities and differences that you see in campain commercials from 1950s to 2010. Although discussing issues of style (length, etc.) is OK, please make sure your analysis goes beyond mere issues of style. Your analysis should make reference to specific things that occur in the ads, and a thematic organization is preferable to a chronological one.