As the New Jersey legislature prepares to take up a law allowing gay and lesbian couples, the debate highlights the differing levels of support in different age groups:

A national CNN poll this year showed that 58 percent of those under 30 back gay marriage, while only 24 percent of those over 65 do. This generational divide is the size of the Grand Canyon.

It means that history is on the side of marriage equality. Younger people are simply not as rattled by homosexuality, perhaps because they have lived among more openly gay people. They don’t consider it a personality defect, or a moral wrong. And they don’t want treat their gay friends and relatives as something less.

So gay marriage will happen. The only question is when.

The Senate will probably vote on this Thursday, and the odds are long. Democrats are rattled after their defeat in the governor’s race last month, and intimidated by the muscular show of force from the Catholic Church in the last few months. The defeats in Maine and New York were both setbacks.

Opponents will emphasize tradition and religion, and a more fanatic fringe will say that homosexuality is deviant.

Some will argue that we need a referendum on the issue, as if the legal rights of a minority should be subject to approval by the majority. A historical note: When the Supreme Court struck down state bans on interracial marriage, 73 percent of American were opposed to mixed marriage, according to a Gallup poll.

Read more in the New Jersey Star Ledger.