Final answer:
The 18-25 age group is the largest but least likely to vote on election day due to various factors.
Step-by-step explanation:
The age group that is the largest of any voting demographic but least likely to show up on election day to cast a ballot is the 18-25 group. This age group, also known as the youth vote, often faces barriers such as lack of political engagement, busy schedules, and a belief that their vote doesn't make a difference. Despite being a significant portion of the voting population, their turnout rates tend to be lower than older age groups.
Learn more about voter demographics