The average voter is average. The U.S. isn’t Lake Wobegon, where all the women are strong, all the men are good looking, and all the voters are above average. :-) It’s that whole Bell Curvey thing. LOL.
And as @ETpro also points out the “average voter” is probably more intelligent than the “average American” because they are at least engaged in their own democracy and understand the importance of being engaged than people who don’t vote.
People back and vote for a particular candidate for all sorts of reasons. Some look at the big picture, some are issues voters, even one issue voters, e.g., they might like everything about a candidate but … if that candidate is pro-abortion they won’t support that candidate.
Maybe it’s less about being stupid and not looking at the big picture, people voting “knee-jerk” because of certain issues that are key to them. People can be ideologues, people vote for candidates who agree with them on key issues. That’s kind of how is works. We have a representative democracy. People vote for candidates who they feel best represent them.
And sometimes, as my mother used to say, you just have to go into the voting booth and hold your nose, because your choices stink, but you don’t give up on the process. Voting, being engaged in the political process, is both your right and your responsibility.
Democracy is not something you just believe in; it’s something you do.
Jumping off my soapbox now.