WASHINGTON — An audience predominantly supporting same-sex marriage that packed a Senate hearing Wednesday tried hard to observe Senate customs frowning on applause or boos, but hundreds burst into laughter several times when outnumbered gay marriage opponents tried to make their points.

The first murmurs came during a contentious exchange between Sen. Patrick Leahy, D-Vt., and Focus on the Family Vice President Thomas Minnery. Leahy asked Minnery if children of same-sex couples—who are ineligible for federal tax breaks available for married couples—suffer because of their parents’ decreased income.

Minnery repeatedly avoided a definitive answer, saying children with gay parents are “better off than having no home at all,” and that it was difficult to answer the question without knowing specifics of a situation.

Leahy cut off Minnery, eliciting chuckles from audience members, and asked for a yes or no answer.

“Yes,” Minnery said, without further comment.

“I’m glad [Leahy] tried to pin him down,” said Bonnie Grabenhofer, vice president of the National Organization for Women. Grabenhofer handed out rainbow-colored stickers supporting same-sex marriage as audience members took their seats.

The Senate Judiciary Committee hearing was called to consider Sen. Dianne Feinstein’s proposed repeal of the Defense of Marriage Act, which says marriage only occurs between a woman and a woman and states do not have to recognize gay marriages performed in other states.

Sen. Al Franken, D-Minn., also took Minnery to task when Minnery cited a study that he said proved children were healthier when raised in a home with one male and one female parent. Franken clarified that the study cited “a nuclear, two-parent home” with no mention to the gender of the parents.

“I would think nuclear family would mean a husband and wife,” Minnery said.

“It doesn’t,” Franken said flatly, garnering waves of laughter reminiscent of his days as a comedian.

But the biggest laughs—and the most eye-rolling—came when Edward Whelan, president of the Ethics and Public Policy Center, said repealing the Defense of Marriage Act would pave the way for “polyamorous” marriage, which he claimed was a “current project of the left.” Polyamorous relationships involve multiple, simultaneous intimate relationships.

Sens. Orrin Hatch, R-Utah, and Charles Grassley, R-Iowa, were the only Republicans to attend the hearing, although neither stayed for the full proceedings.