PHOENIX — Hoping to create a change in attitudes, a coalition of civil-rights groups is taking the first steps today to convince Arizonans that letting gays wed would be a good thing.

The education campaign being launched comes five years after 56 percent of those who went to the polls voted to amend the Arizona Constitution to define marriage in this state as strictly between one man and one woman. Supporters of rescinding the ban contend there are Arizonans who can be convinced — if not now, then by 2016 — to support repeal.

They say there already is evidence of a sharp change in public attitudes.

“For example, Wisconsin in 2006 passed a similar amendment,” said Paul Guequierre, a spokesman for the Human Rights Campaign, one of several groups involved in today’s event. “And yet this past year, (they) elected their first openly gay senator in history.”

Democrat Tammy Baldwin is the first openly gay member of the U.S. Senate from anywhere.

Cathi Herrod, president of the Center for Arizona Policy, said supporters of gay marriage are reading far too much into last year’s election of Baldwin, a seven-term member of Congress who edged out former Republican Gov. Tommy Thompson.

“I would not say that the voters of Wisconsin elected that senator because of her sexual orientation and that reflects a change in attitudes,” Herrod said. “People judge candidates on the basis of their qualities, where they stand on the issues.”

And Herrod already is laying the groundwork to make the debate more personal for voters than just questions of equal treatment under the law.

“In the state of Massachusetts, parents no longer have the right to oversee what kinds of books that 6-year-olds had to read in school,” she said. That refers to a federal court ruling that concluded parents have no right to object when elementary-school youngsters are given books showing nontraditional families, even if that conflicts with parents’ religious views.

“Regardless of where you are on the marriage issue, talking to your children about same-sex relationships should be reserved for the parents when a child’s only 6 years old,” Herrod said.

Arizona’s political landscape is mixed.

Voters in at least parts of Arizona have shown that issues of sexual orientation do not matter.

As early as 1996, residents of parts of Tucson and Southeast Arizona re-elected Republican Jim Kolbe to Congress, even after he was forced to reveal his sexual orientation after being threatened by some gay organizations to “out” him. More recently, Pinal County voters returned Sheriff Paul Babeu to office last year, aware that he was gay and after a photo emerged of the underpants-clad sheriff taking a picture of himself to post online.

And a far-reaching 2006 ballot initiative to ban both gay marriages and civil unions was narrowly defeated. But that led to the scaled-back 2008 measure confined to the issue of who can wed, which won strongly.

The key is going to be moving the needle enough so gay marriage supporters feel confident a 2016 ballot measure would not be a waste of time.

A statewide poll earlier this year of 700 adult heads of households found that 55 percent said they would support allowing gays and lesbians to wed, with just 35 percent opposed.

But translating that to support at the ballot box might be something else.

The survey showed those who identified themselves as registered Republicans remain sharply opposed, with just 36 percent in support of repealing the measure. The key could come in getting Democrats and independents, both groups firmly backing gay marriage, to turn out on Election Day.

While supporters of repealing the constitutional amendment are unveiling their own education campaign, Herrod has promised an equally vociferous response from the other side.

It may come down to a question of timing.

So far 13 states have laws allowing gays to wed. And Herrod conceded there has been no significant fallout, to the point where any state is already considering reversing course.

But Herrod argued said the full effects have yet to be felt.

“We’re less than a decade into states redefining marriage,” she said.

Also involved in today’s event is the American Civil Liberties Union of Arizona and Equality Arizona.