Three years ago, when Neil Abercrombie was running for governor, former Honolulu Mayor Mufi Hannemann tried to bait him into a corner on gay marriage.

During a Democratic primary debate, Hannemann said the important question was not civil unions, but whether he or Abercrombie would eventually legalize gay marriage if elected.

"That question is not before us," Abercrombie said, "and is unlikely ever to be."

On Monday, the state House and Senate — called back to the state Capitol by Gov. Abercrombie — will convene a rare and potentially historic special session on gay marriage.

Hawaii could follow 14 states and the District of Columbia and approve marriage equality. Gay and lesbian couples could marry as soon as Nov. 18.

The evolution on gay marriage in Hawaii is part of a shift in public opinion across the United States as political leaders — too timid to even mention the possibility a few years ago — are now framing the issue as an obvious matter of equity.

Hawaii-born President Barack Obama’s decision to endorse marriage equality last year helped tip the balance within the Democratic Party. The U.S. Supreme Court rulings in June that legally married gay couples are entitled to federal benefits created the urgency.

Voters in 1998 had overwhelmingly approved a constitutional amendment that gave the Legislature the power to define marriage as between a man and a woman. At the time of the primary debate in 2010, Gov. Linda Lingle had just vetoed a civil-unions bill that dramatically cleared the Legislature on the last day of the session.

Abercrombie, as a candidate, had promised to sign civil unions into law if elected but would go no further.

"I haven’t evolved in this issue at all," the governor said in an interview Friday. "It’s the issue that has evolved."

Abercrombie said he supported the constitutional amendment in 1998 because he believed the Legislature should have the authority to define marriage. He said he favored civil unions — and maintains the law should have been approved much sooner — because he thought most people were not ready for a discussion on marriage equality.

The governor said the civil-unions law helped change attitudes.

"The sun comes up. The world keeps turning," he said. "And they’re beginning to run into people who are involved in these relationships."

Abercrombie has described the gay-marriage bill as "doing what is right to create equity for all in Hawaii," but has also used practical considerations to justify the special session. Gay couples in Hawaii are unable to enjoy federal benefits unless they can marry.

"Any time you have a benefit delayed that is due you, then it’s being denied," the governor said. "There are serious tax consequences coming up in January."

NATIONAL POLLING by Gallup has marked the evolution. In 1999, 35 percent of respondents thought same-sex couples should have the same rights as traditional marriages. By last July, 54 percent thought same-sex couples should be treated equally. Private polls taken for gay-rights advocates in Hawaii have shown a similar trajectory of growing acceptance.

"I think there is more acceptance," said Camaron Miyamoto, the coordinator for lesbian, gay, bisexual, transgender and intersex student services at the University of Hawaii at Manoa. "And there is a greater understanding of compassion, love and aloha."

Miyamoto described it as a "new tide" that is unlikely to reverse.

"This is a human rights issue," he said. "I know that we’re making history right now. And I’m proud that it’s happening in Hawaii."

Steven Levinson, who as associate justice of the state Supreme Court wrote the landmark Baehr v. Lewin decision in 1993 that held that denying same-sex couples marriage licenses was a violation of equal protection, said he did not believe it would take Hawaii so long to reach this point.

"No, I didn’t," the retired judge said. "Although I was pretty naive at the time regarding my expectations for the state."

State lawmakers responded to the court’s ruling by placing the constitutional amendment before voters in 1998 that gave the Legislature the power to define marriage as between a man and a woman.

Levinson said the courts are often out in front. It took a decade after the U.S. Supreme Court ended segregation in public schools with the Brown v. Board of Education decision in 1954 for Congress and President Lyndon B. Johnson to cement racial equality though the Civil Rights Act of 1964.

"It took the passage of time, and the normalization — maybe demystification — had a lot to do with it," the judge said. "If you don’t ever have to deal with people who aren’t just like you, you can perpetuate the stereotypes and preconceptions and myths about what those other people are like.

"But the more you interact, the more you realize that we’re all basically the same. And that changes perception."

Levinson predicts a similar future for marriage equality as more states take action after the Supreme Court’s ruling that legally married gay couples are entitled to federal benefits.

"I think when a certain critical mass is reached nationwide — state by state, and that probably will not include most of the South — the United States Supreme Court will perceive a federal right of same-sex marriage somewhere, either as a function of equal protection or as a function of due process.

"And when that happens, the ball game will be over."

MANY HAWAII Democrats have made the political calculation that the game is already over.

One by one, Democrats, especially those seeking higher office, have followed the party’s platform and publicly embraced marriage equality. U.S. Reps. Tulsi Gabbard and Colleen Hanabusa, state Sen. Will Espero (D, Ewa Beach-Iroquois Point) and state Rep. K. Mark Takai (D, Halawa-Aiea-Newtown) have changed their views within the past two years.

The political risk for Democrats who control the Legislature is in going against the tide of their party, Obama, Abercrombie and their leadership. The risk from a primary opponent or Republican challenger who opposes gay marriage is largely a secondary threat, particularly after there was no political fallout for Democrats after passing civil unions.

While many Democrats have long believed in marriage equality and have waited for their colleagues and public opinion to catch up, some are making the practical determination that if the Legislature does not act now, the courts soon will. Jackson v. Abercrombie, the legal challenge by gay couples to the state’s marriage law, is on hold before the 9th U.S. Circuit Court of Appeals pending the special session.

No Democratic lawmaker has been willing to publicly lead the opposition to gay marriage, although a few, such as Rep. Marcus Oshiro (D, Wahiawa-Whitmore-Poamoho), have warned against the rush to pass a bill in special session and have called for a stronger religious exemption.

Rep. James Tokioka (D, Wailua-Hanamaulu-Lihue), who intends to vote against the bill, said he surveyed constituents in his district earlier this year and found that 70 percent of respondents opposed same-sex marriage.

"I need to reflect the opinion of my district," he said.

The projected vote count for marriage equality in the state Senate is 21-4. In the state House — where individual districts are smaller and the intensity of public opinion can feel closer — several lawmakers appear nervous. The Star-Advertiser’s vote count in the House remains at 28-17, with six lawmakers undecided. House leaders say their count is closer to 30 in support, a cushion over the 26 votes required for passage.

The House Democrats who say they are undecided — and who will likely experience the full force of the public over the next several days — are still calculating.

Two years ago, when the House voted for civil unions, Rep. John Mizuno (D, Kamehameha Heights-Kalihi Valley), a Christian, told his colleagues that "my ‘no’ vote represents my steadfast commitment and understanding of our God."

Earlier this year, Mizuno, who is now the House vice speaker, thought voters should decide the issue of marriage through a constitutional amendment. After the Supreme Court’s rulings in June, he said the Legislature should decide and that he was reconsidering his own opinion.

Today, Mizuno says he is nearing a "complete evolution."

"In order for me to vote ‘yes’ on this bill, I will need two guarantees," he said in an email. "First, that the bill clearly protects the free will and choice of those wishing to love, honor and commit their life in marriage to another, regardless of their sex. Secondly, and just as important, the bill will need to embody robust language to protect the churches, mosques, synagogues, other places of worship and those that lead them, with exemptions that ensure that their constitutional right to freedom of religion is protected.

"As a lawmaker, I cannot side with either group if they aim to take away the rights of the other. What I can do, what I swore an oath to do as a representative of the people of this state, is to protect and represent the rights for all people. This bill will have to clearly guarantee the rights of both sides for me to vote ‘yes.’

"I am nearing complete evolution of my position on this issue, but must reserve my vote pursuant to the final language of the bill agreed by both houses."