Topeka ? A proposed constitutional amendment to ban gay marriages and prevent Kansas from granting other forms of legal recognition to same-sex relationships received a House committee’s endorsement Tuesday.

A 1996 Kansas law already says the only valid marriages in Kansas are between one man and one woman. The proposed amendment would add a similar statement to the constitution, plus a prohibition on granting benefits associated with marriage to other relationships.

On a voice vote, the Federal and State Affairs Committee sent the measure to the entire House for debate.

“If we want to have that law and protect that law, then this probably needs to be in the constitution,” said committee Chairman Bill Mason, R-El Dorado, a supporter of the proposal.

If two-thirds majorities in both legislative chambers adopt the proposed amendment, it will be submitted to voters in the Nov. 2 general election, when a simple majority will be necessary to change the constitution. Both supporters and opponents expect voter approval.

Backers of the amendment said they want to prevent a Kansas court from invalidating the law prohibiting gay marriages, just as Massachusetts’ highest court struck down a similar “defense of marriage” statute in that state.

Thirty-three states, including Kansas and Massachusetts, have similar laws, but legislators in at least 15 of them are considering constitutional changes. Four states already have constitutional provisions against same-sex marriages: Alaska, Hawaii, Nebraska and Nevada.

In a hearing last week, supporters of the Kansas amendment often touched on long-standing religious values in opposing gay marriages. They also said traditional marriages form the most stable families and the best environment for raising children.

“There’s no evidence that gay families create the stability in society we’re looking for,” said Rep. Dan Williams, R-Olathe.

As for a same-sex relationship, Williams said, “I think a majority of Kansans and a majority of Americans would disagree that is a normal, healthy relationship.”

But Rep. Jan Scoggins-Waite said the proposed amendment could be considered “homophobic.”

“It just doesn’t seem fair,” she said. “All of a sudden, we’re taking one group of people and saying, ‘Sorry, we don’t like you.'”

The amendment originally dealt with only marriage and did not address other forms of legal recognition for same-sex relationships, such as Vermont-style civil unions or domestic partnerships.

But on an unrecorded 12-6 vote, the committee made amendments suggested by Williams to prevent the state from authorizing civil unions or domestic partnerships.

“If we ban marriages but leave a loophole for civil unions, they’ll be here in a heartbeat,” Williams said after the committee meeting.

Rep. Rick Rehorn, of Kansas City, the committee’s ranking Democrat, unsuccessfully sought to put the amendment on the Aug. 3 primary election ballot, rather than the general election ballot. He said his plan would allow the ban to take effect earlier.

But others noted that voter turnout in primaries often is only a fraction of the turnout in general elections.

Privately, some Democrats worry that having the constitutional ban on same-sex marriage on the November ballot will mobilize conservative Republicans, hurting Democratic candidates, including U.S. Rep. Dennis Moore, who is seeking his fourth term in the GOP-leaning 3rd Congressional District.