Oprah's Endorsement Worth A Million Votes For Obama

Kevin Drum has an interesting post about an article which attempts to quantify the impact of Oprah Winfrey's early endorsement of Barack Obama during the Democratic presidential primary campaign. Economist Professors at the University of Maryland Craig Garthwaite and Tim Moore in their paper "The Role of Celebrity Endorsements in Politics:
Oprah, Obama, and the 2008 Democratic Primary" (pdf), the authors assert that Oprah's early endorsement resulted in approximately 1 million votes for Obama.

Candidates in major political contests are commonly endorsed by other politicians, interest groups and celebrities. Prior to the 2008 Democratic Presidential Primary, Barack Obama was endorsed by Oprah Winfrey, a celebrity with a proven track record of influencing her fans’ commercial decisions. In this paper, we use geographic differences in subscriptions to O! – The Oprah Magazine and the sale of books Winfrey recommended as part of Oprah's Book Club to assess whether her endorsement affected the Primary outcomes. We find her endorsement had a positive effect on the votes Obama received, increased the overall voter participation rate, and increased the number of contributions received by
Obama. No connection is found between the measures of Oprah's influence and Obama's success in previous elections, nor with underlying local political preferences. Our results suggest that Winfrey’s endorsement was responsible for approximately 1,000,000 additional votes for Obama.

The Power of O, indeed!