Impassioned crowds swamped the state Capitol today to tell legislators exactly how they feel about same-sex civil unions: either an attack on traditional marriage or a gateway to equal rights.

Despite the display of participatory government, with more than 1,300 people signed up to testify today, the outcome of the Senate Judiciary Committee hearing appeared predetermined. The full Senate plans to yank the bill from the committee if its vote ends in a 3-3 tie as expected.

The hearing got off to a fiery start with a clash between transgendered state Board of Education member Kim Coco Iwamoto and Democratic Sen. Mike Gabbard, a former Republican who led the fight against gay marriages in Hawaii more than a decade ago.

Gabbard held up children's books with titles like "Daddy's Wedding" and "It's Perfectly Normal" as he claimed that "these books would be taught in our schools" if the civil unions bill passes.

As the crowd groaned and cheered, Iwamoto responded that civil unions would help make children in gay families feel more normal and less likely to commit suicide. Iwamoto, who was born a boy but now lives as a woman, in 2006 won the highest elected post of any transgender person in the country without either hiding her sexual status or making it part of her campaign.

"I want to make sure that these kids aren't thinking, 'Gee, just because that kid has gay parents, let's harass him, let's bully him,' " Iwamoto said. "Our kids get these messages and they impose them on each other in hurtful ways."

Hundreds of red-shirted civil union opponents outnumbered gay rights advocates at the Capitol, with many overflowing from the auditorium into the halls to watch the testimony on TVs set up for the occasion. It was the largest turnout for a Capitol hearing in years.

Civil union backers wore gold stickers with the word "Equality" written on them in green.

Religious groups opposed to civil unions argued that they're the same thing as marriage, which should be reserved to couples of one male and one female.

"It is same-sex marriage under a different name," said Father Marc Alexander, a Catholic priest. "The reason why we benefit and endorse and acknowledge marriage in a special way in our religious structures is because of how it serves the common good in our community."

Civil union proponents told lawmakers that equality is a civil rights issue that should be settled based on principles rather than the will of an oppressive majority. Nearly 70 percent of Hawaii voters approved a constitutional amendment in 1998 granting the state Legislature the power to reserve marriage for opposite-sex couples.

"Where the fundamental civil rights of an unpopular minority are at stake, the principle of 'letting the people decide' is often a mere cloak for majoritarian tyranny," said Linda Krieger, a University of Hawaii law professor and adviser for a group of students advocating gay rights.

If the committee vote ends in a tie, chairman Sen. Brian Taniguchi, D-Moiliili-Manoa, has said he supports pulling the bill from the committee and putting it up for a vote of the full Senate, where at least 18 of the 25 senators have said they favor civil unions. The measure already has passed the Hawaii house.