However, the opposition -- while still divisive -- is "not nearly as inflammatory as gay marriage," said Andrew Kohut of the Pew Research Center for the People and Press.
"With gay marriage there's the whole question of what marriage represents, in what's a religious ceremony for many people," Kohut told The Christian Science Monitor.
"With adoption we have the issue of children who are uncared for being taken care of. There are all kinds of crosscurrents that will be there that aren't there for gay marriage," he said.
Seven states introduced bills last year to bar adoptions bys gay and lesbian couples.
Florida, Mississippi and Utah explicitly ban same-sex adoptions -- a proposal being considered in Ohio -- while states such as Arkansas, Nebraska, New Hampshire and Missouri restrict gay and lesbian adoptions, the newspaper reported.