Why would you ask for the youngest adult? Is that a normal polling procedure?
In this house parents are conservative, voting age child is liberal our won’t vote.
Are you sure they did that for the whole poll?
Years ago I would track down poll methodology and post about it here. Amazing the stuff they will do, like take those who think a democrat is doing a poor job, and include them in the positive approval column.
They ask for the youngest adult because young people are less likely to answer the phone and a large percentage do not have landlines.
Interviewing the youngest adult allows the pollster to not have to weight that sample as heavily.