The US Census Bureau recently released an analysis of who voted in the 2014 election, based on a survey of Americans taken in November. And it revealed some fascinating statistics about the makeup of the midterm electorate.
Overall, 41.9% of citizens who were at least 18 years old came out to vote, which the Census Bureau noted was the lowest turnout in any election since 1978, the year the Bureau began its survey. Presidential election years tend to see far higher turnout than midterm congressional elections. For example, 61.8% of eligible Americans voted in the 2012 presidential election.
Older Americans were much more likely to vote than younger Americans. Men and women were about balanced, with a slightly higher proportion of women voting. A higher proportion of whites voted than other racial groups. Married people were about twice as likely to vote as those who had never been married, and for the most part, Americans with higher education and income were more likely to vote.
As this is a survey, there are some discrepancies with official total vote counts, as some people who didn't vote might have told the survey interviewer they did. Despite that caveat, this is still a pretty good picture of the demographic breakdown of the voting public.
Here's the Census Bureau's demographic breakdown, showing the percentage of each subgroup of adult citizens who self-reported voting in 2014:
Business Insider/Andy Kiersz, data from US Census Bureau