The following graph shows, by political orientation and over time, the ideal number of children GSS participants think a family should have and the actual number of children they do have:
There are a lot of intersections on the graph that make it more challenging to follow than it should be. The light colors trace the ideal number of children; the dark lines actual number of children. To allow for family formation to have occurred and also to keep the age range within reason in relation to the total time period under consideration, figures for actual number of children are restricted to those aged 35-65.
Two more remarkable aspects are, 1) that the ideal number of children a family should have has remained remarkably consistent over the life of the survey and varies very little by political orientation, and 2) that a couple of generations ago, people tended to have more children than they perceived to be ideal while today they have fewer than they believe to be ideal.
GSS variables used: CHLDIDEL(0-7), CHILDS, POLVIEWS(1-3)(4)(5-7), AGE(35-65), YEAR