Voter participation is highest in presidential election years, followed by midterm election years. Municipal election years attract the least number of voters. While the intrinsic reasons for the year-to-year fluctuation of voter turnout are difficult to know, there is concrete data that explains the varied participation. That data is the share of the voter registration population, the share of the vote and the voter turnout for age group categories which are typically the subject of election day exit polls, 18-29, 30-44, 45-64 and 65 plus.
The age groups data shows that voters that are 18-29 and 30-44 years old always under-perform. That is, the share of the vote these groups comprise is always lower than their share of the voter registration population. More importantly, the under-performance is more pronounced in non-presidential elections. For example, in the 2016 presidential election, the age groups of 18-29 and 30-44 years-old comprised 48 percent of the registered voters and 41 percent of the actual voters. In comparison, in the 2014 midterm elections, the age groups of 18-29 and 30-44 years-old comprised 47 percent of the registered voters and only 28 percent of the actual voters.
The under-performance of the 18-29 and 30-44 years-old age groups is easier understood by examining the voter turnout. In the 2016 presidential election 18-29 year old voters turnout at 45 percent and 30-44 year-old voters at 55 percent. In comparison, in the 2014 midterm election, 18-29 year old voters turnout at 14 percent and 30-44 year old voters at 24 percent.
In essence, the inconsistent voter participation of the 18-29 and 30-44 years-old age groups makes the 45-64 and 65 plus age groups more prominent. It increases the share of the vote of the older groups making them account for a percent of the votes cast that is beyond their share of the registered voter population. And the disproportionate participation among the electorate has an impact on the outcomes of an election.
