"The problem is, when you give it a different name, people routinely think of it as different status," Goldfarb said. "We've been trying for close to five years and people still don't know what civil union is."
The issue, though, is "bigger than just the word" marriage, Christie said, and changing the law affects "everyone" - not just gays.
"It's hundreds of years of tradition . . . legally, societally, and religiously. And that's what I stand up for and am protecting," he said.
At the same time, he said, there's nothing "so special about this particular issue that it must be handled by a legislature."
"The fact of the matter is, I think people would have been happy to have a referendum on civil rights rather than fighting and dying in the streets in the South," he said.
Referendums on issues deemed by supporters to be civil-rights matters have a mixed history.
In 1915, New Jersey put a referendum on the ballot for women's suffrage. It failed, said Ronald Chen, former public advocate under Gov. Jon S. Corzine. At Tuesday's hearing, he presented a letter from 127 law professors from around the country who said the civil union law, which provides some of the rights of marriage, cannot be fixed.
More recently, voters in Maine overturned a state gay-marriage law, while California voters banned same-sex marriage by referendum in 2008. Similar referendums are pending elsewhere.
Washington State is on the verge of approving gay marriage through legislative approval and gubernatorial signature, but opponents then plan to have a question put on the ballot rolling it back.
A similar situation is playing out in Maryland. There, the governor and other backers of a same-sex-marriage bill are trying to head off objections by including in it legal protections for religious groups that decline to conduct such marriage ceremonies. The measure proposed in the New Jersey legislature also contains similar protections.
Monmouth University pollster and political scientist Patrick Murray said Christie's proposal indicates that "politically, he doesn't want his fingerprints anywhere near this."
Although vetoing the bill could help him if he ran in the 2016 presidential GOP primary, Murray said, it would also allow New Jersey Democrats during a 2013 reelection bid "to paint him as someone who kowtows to the socially conservative wing of the party and is not concerned with his constituents here in New Jersey."
