The American Family Association is urging support for a proposed amendment to the U.S. Constitution by Rep. Tim Huelskamp, R-Kan., that would define marriage as one man and one woman. The proposal comes after a legal scholar admitted that the arguments used to justify same-sex marriage will pave the way for legalization of polygamy and incest. The American Family Association is urging support for a proposed amendment to the U.S. Constitution by Rep. Tim Huelskamp, R-Kan., that would define marriage as one man and one woman. The proposal comes after a legal scholar admitted that the arguments used to justify same-sex marriage will pave the way for legalization of polygamy and incest.