Led by state Senate President Stephen Sweeney (D), a recent convert to supporting gay marriage, Democratic lawmakers in New Jersey pledged earlier in the year to make the issue a top priority for the legislative session.

That move intensified the pressure on Christie, a moderate Republican who has shied away from divisive fights on social issues, but whose rising profile in the national Republican Party has created a disincentive for him to cave to New Jersey Democrats.

"I need to be governed by the will of the people. And the best expression of the will of the people is not a poll, it is an election," Christie said. "So, let’s put it on the ballot."

The reactions to Christie's call for a referendum were mixed. Supporters of gay marriage argued the rights of minorities should never be left up to the whims of the majority — even though polling suggests most people in New Jersey support gay marriage.

Others speculated that Christie was giving himself a political out by devising a way for gay marriage to pass without his fingerprints; a statewide referendum would not be subject to Christie's veto.

Even if Christie vetoes the bill approved Thursday, its passage adds to a growing list of accomplishments by those who are eager to make what they deem a civil rights issue into a major component of the 2012 election cycle.

The Maryland House of Delegates was scheduled to debate a gay marriage bill on Thursday, with a vote expected Friday and a Democratic governor who has already said he would sign it. Washington Gov. Christine Gregoire (D) signed gay marriage into law last week. And a federal appeals court in California struck down that state's voter-approved ban on gay marriage earlier in February, calling it a violation of the U.S. Constitution.

An effort is also underway to persuade the Democratic Party to add gay marriage as a plank of the party platform for the national convention in September. House Minority Leader Nancy Pelosi (D-Calif.) said Thursday she personally supports such a move.