There are many interesting talking points on his list. A couple of points deal with the correlation between the permanence of marriage and wealth. In fact, it is very interesting that he wants to emphasize the “inequality” aspects of the marriage debate, which would seem to relate to the loss of disposable income when people raise children, as well as the growing “burdens” of eldercare because of demographics, which no one can escape just by abstinence.
I see that the New York Times also has a story by Mark Oppenheimer, "In shirt, activist enlists same-sex couples in pro-marriage coalition", link here. The article talks about the difficulty in "raising money" for moderate positions that actually would encourage marriage and reinforce external respect for the institution.