Arizona Representative Trent Franks last week made the incorrect claim that gay and lesbian couples don't make good parents.

Appearing on the Family Research Council's (FRC) Washington Watch radio program, the Republican lawmaker linked marriage equality to the recent House fight over efforts to approve LGBT nondiscrimination rules for federal contractors.

Franks then claimed that “all of the research shows” that children raised by heterosexual couples perform better “on every measurable metric” than kids raised by gay couples.

“There is no doubt whatsoever that whether it's caused by divorce or lack of marriage or same-sex marriage, whatever it is, whenever a child is not in a mother-father family, traditional family, they have some odds stacked against them in many areas,” Franks said.

Most researchers agree that children raised by gay parents are at no disadvantage. And there is some research to suggest that the children of same-sex couples fare better in certain areas.

Franks, a vocal opponent of LGBT rights, also told FRC President Tony Perkins that liberals “can't have a reasoned discussion because most of their positions simply collapse under the weight of reason.”