Final answer:
The average American is typically part of the party-in-the-electorate, which encompasses voters who identify with or prefer a particular political party's candidates.
Step-by-step explanation:
The average American likely belongs to the party-in-the-electorate, which consists of the members of the voting public who consider themselves to be part of a political party and/or consistently prefer the candidates of one party over the other. This is the broadest and most inclusive component of a political party and represents everyday citizens who align themselves with a party's ideals and vote accordingly.
In contrast to the party organization, which is more about the formal structure and active members coordinating party behavior, and the party in government, which involves the elected officials, the party-in-the-electorate is the most fundamental and extensive component that any average voter is likely a part of.