In an unprecedented public divergence with Gov. Chris Christie, Newark Mayor Cory Booker said today he is firmly against leaving the question of gay marriage up to a referendum.

"I shudder to think what would have happened if the civil rights gains, heroically established by courageous lawmakers in the 1960s, were instead conveniently left up to popular votes in our 50 states," Booker said in a statement.

With the gay marriage debate advancing in Trenton today, Gov. Christie, who has long said he would veto a gay marriage bill, said "I need to be governed by the will of the people."

But Booker countered that leaders are elected to make difficult decisions, not submit to a public referendum.

"Equal protection under the law – for race, religion, gender or sexual orientation – should not be subject to the most popular sentiments of the day," Booker said. "Marriage equality is not a choice. It is a legal right. I hope our leaders in Trenton will affirm and defend it."