John Eastman, chairman of the National Organization for Marriage (NOM), has claimed that majorities in only 5 states where gay marriage is legal support the law.

Speaking on The Drew Mariana Show last week, Eastman predicted that court rulings favoring marriage equality proponents would provoke a massive grassroots movement demanding a constitutional amendment defining marriage as a heterosexual union.

“I suspect there will be such an impetus for a constitutional amendment that we may see that actually take root,” Eastman said. “And remember it takes 34 states to call for a constitutional convention and there are 33 that continue to adhere to traditional marriage and about another dozen that the people have never changed away from that position.”

There are 17 states plus the District of Columbia that allow gay and lesbian couples to marry. A majority of these laws were adopted either by state lawmakers or voters, including Washington, Vermont, Minnesota, Illinois, Hawaii, New York, Maryland, Maine, Delaware, Rhode Island and New Hampshire. Marriage equality also came to the District of Columbia through the enactment of an ordinance approved by lawmakers. Wide support for gay nuptials existed in New Mexico, California and New Jersey before each moved into the marriage equality column earlier this year. Polls conducted in 2012 found majority support for same-sex marriage in Connecticut (55%) and Massachusetts (62%). A Des Moines Register poll conducted early last year found a majority (56%) of Iowans oppose passage of a state constitutional amendment which would ban gay marriage in the state.