Tuesday, July 27, 2010

Over-representation in the electorate

Ezra Klein put together some Census and exit poll data yesterday to produce a table showing which income groups are over- or under-represented in the electorate and how those groups voted in 2008.  But why do a table when you can make a graphic?  In the chart below, higher red bars indicate more Democratic income groups, and higher blue bars indicate over-representation of particular income groups in the electorate.
The chart nicely shows that the most under-represented segments of the population are, in fact, the most Democratic.  (Ezra calculates this cost Obama 2.3 percent of the vote.)  Interestingly, the most over-represented groups are not the wealthiest, but those making between $50,000 and $100,000 a year.

1 comment:

Anonymous said...

You forgot to rescale by the size of the income cohort. 220K+ people are 6% of the electorate and 3.8% of the population, so their voting representation is 158% of their population share.

In contrast, the 50-75K cohort has "only" 117% of their expected voting share.

By the same scale, the voting power of the poorest cohort is under half of their population share.