This whole thing verges on “silent majority” thinking. The people who don’t vote have no bearing in this calculation. If they cared either way, they would have voted.
If we just talk about the people who voted, and who they voted for, then almost half of them voted for Trump, almost half of them voted for Harris (although a slightly lesser "half" than Trump).
If you want talk about people who didn't vote and how they would vote, young people (over 18 but under 30) are less likely to vote and participate in polling services like KnowledgePanel. But they didn't vote so whatever.
It’s particularly suspect with Trump, because of his strength among infrequent voters. https://abcnews.go.com/538/vote-back-trump/story?id=10909062...
“But among respondents who were old enough to vote but voted in none of those three elections, Trump crushed Biden 44 percent to 26 percent.”