CIRCLE estimates that 23% of young Alabamians voted in yesterday’s special election. Just for a rough turnout comparison, 21.5% of youth in the United States as a whole voted in the 2014 election. We would normally expect turnout to be lower in a special election with only one person on the ballot than in a national Congressional election, and also lower among Alabama youth than youth across the country because just 40% of young Alabamians have any college experience (and college is correlated with voting). Thus I would call the turnout pretty good compared to expectations.
According to the Exit Polls, youth supported Doug Jones over Roy Moore by 60% to 38%. The older vote was dramatically different, with Moore winning people over 45 pretty easily. CIRCLE suggests two interesting contributing factors. First, young Alabamians are more diverse. “More than a third of the state’s young people are Black, and … Black voters of all ages went overwhelmingly for Jones (96%) in yesterday’s race.” Second, Moore may not have “garner[ed] overwhelming support even among youth who identify as conservative or Republican.” CIRCLE has previously found that “some Republican-leaning youth break with older voters on same-sex marriage and other social issues that were central to Moore’s campaign in Alabama. In addition, CIRCLE analysis of the Pew Research Center’s Political Typology dataset finds that only 5% of young people who lean toward or belong to the Republican party are “Steadfast Conservatives” (compared to 25% of Republicans or Republican-leaners aged 30+) while 31% are “Young Outsiders” who may feel less committed to the party and its candidates.”
More detail is on the CIRCLE website.