Richard Wolf

USA TODAY

Note: This story was written last week before the Supreme Court's surprise decision not to take up the cases this term.

WASHINGTON — As the Supreme Court prepares to decide the future of same-sex marriage — an institution described as "newer than cellphones or the Internet" by one justice last year — two things are clear.

Despite this year's breathtaking string of lower court victories, the battle for marriage equality hasn't been swift or easy. To the lawyers who devised the legal strategy decades ago, the journey has been arduous, the setbacks plentiful and the battle scars deep.

And even after the high court rules — most likely by striking down state bans on gay marriage at the end of its term in June — the fight won't be over. Another clash looms over the issue of religious freedom.

Same-sex marriage's transformation from impossible dream decades ago to all but inevitable today has been, by most accounts, unprecedented. First legalized in the Netherlands in 2001, gay and lesbian marriages have spread to 19 countries and 19 states.

As they stand at the precipice — with the high court delaying any decision Thursday but likely to accept one or more cases later this month — the movement's founders insist it's a cause whose time has come.

"Every day literally matters," says Evan Wolfson, who launched the advocacy group Freedom to Marry in 2003 and hopes to put it out of business next year. "People are literally dying without being able to get married."

Before same-sex marriage went on its current winning streak, however, there was a very long losing streak. In 1972, the Supreme Court tossed out the first gay marriage lawsuit "for want of a substantial federal question." In 1986, the justices upheld states' rights to ban homosexual sodomy. The 1990s brought progress, but not victory, from Hawaii to Vermont.

"The tone of the opinions from the state courts was as though a man was seeking the right to be pregnant," recalls Mary Bonauto, the godmother of the gay marriage movement, who won the first victory in Massachusetts in 2003.

The air of inevitability that pervades the issue today stems from a near-perfect string of court victories since June 2013, when the Supreme Court ruled 5-4 that the federal government must recognize same-sex marriages performed in states where it is legal. The same five justices appear likely to take the final step this term by declaring state bans against gay marriage unconstitutional.

Standing in the breach are the same steadfast opponents who have defended the states' prohibitions for two decades. They have not given up hope that the justices will come down on the side of states' rights. But even if they lose, they promise more battles to come between gay rights and religious rites.

"There's a ton that will happen on religious liberty. We're already preemptively moving in this direction," says Brian Brown, president of the National Organization for Marriage. "The other side wants to push religious liberty into the four walls of a church."

'IMPOSSIBLE DREAM' TAKES ROOT

That movement was born in the wake of Loving v. Virginia, the 1967 Supreme Court decision that outlawed state bans on interracial marriage. Yet the years that followed did not produce immediate victories.

The Supreme Court refused in 1972 to overrule Baker v. Nelson, which upheld a Minnesota law denying marriage rights to gay men and lesbians. "It was a train wreck," says James Esseks, director of the American Civil Liberties Union's LGBT and AIDS Project. "It's a case that has haunted us for decades."

The 1980s brought Bowers v. Hardwick, which upheld Georgia's law banning homosexual sodomy. Other cases were filed -- and lost — on behalf of gay couples.

The effort began to take root in the 1990s, when proponents won their first court victory in Hawaii. The reaction was swift: Congress passed the Defense of Marriage Act in 1996, denying federal recognition to same-sex marriages that did not yet exist. Hawaii voters passed a constitutional amendment against same-sex marriage in 1998, making the matter moot.

Another victory came in Vermont in December 1999, but it, too, was short-lived. The state Supreme Court ruled that gay men and lesbians should have the same rights as heterosexuals, leaving it to the Legislature to decide how. The result, in 2000, was civil unions — not marriages

Not until 2003 did Massachusetts become the first state to legalize gay marriage in Goodridge v. Department of Public Health, a case won by Bonauto. That same year, Paul Smith won Lawrence v. Texas, which struck down the remaining state laws against sodomy. That was a major victory in the fight against discrimination. But beyond one state, marriage remained elusive.

"It was considered an impossible dream by some," Smith recalls. "Some gay people thought it was a crazy idea themselves.

"Litigation," he says, "changed hearts and minds."

REAL PEOPLE, REAL BENEFITS

After Massachusetts, the deluge didn't come. The legal movement lost cases in New York, Washington, Maryland, Arizona and Indiana. Constitutional amendments banning gay marriage were passed in a dozen states in the fall of 2004.

So a group of about 15 advocates from groups such as the ACLU, the Human Rights Campaign and Lambda Legal met to plot a path through more states to the Supreme Court.

It took nearly five years before legislatures and courts answered the call. California was first, but a court decision legalizing gay marriage was quickly reversed by voters at the polls. Finally, a series of states from New England to Iowa made same-sex marriage legal. California finally became the 13th state last year.

"Every five years is a complete generation in gay rights law," says David Codell, constitutional litigation director for the National Center for Lesbian Rights.

Since then, federal and state courts have given an almost unbroken winning streak to the gay marriage movement, with only a federal judge in Louisiana upholding that state's ban. A total of 19 states and the District of Columbia now permit same-sex marriage, and courts have ruled favorably in 14 other states. Wolfson has been to 10 same-sex weddings this year alone.

Along with the court rulings has come a growing acceptance of same-sex marriage by a majority of Americans. The latest Gallup Poll showed 55% support for gay marriage and 42% opposed.

"If there is one silver bullet you have to point to that has moved public opinion dramatically over the years, it's folks getting to know us," says Chad Griffin, president of the Human Rights Campaign, the nation's largest gay rights organization. "It's been nearly five decades in the making."

Despite those gains, gay rights advocates are trying to draw attention to the continuing hardships faced by same-sex couples.

Those blocked from matrimony are denied the financial benefits enjoyed by heterosexual couples, such as leaving pension, Social Security and veterans benefits to their spouse and avoiding estate taxes upon one partner's death. Non-biological parents are denied adoption rights. Even legally married couples face hassles when they travel to or move to states that don't recognize their marriages.

The differences in local, state and federal benefits translate into real dollars. A study released Tuesday by two liberal think tanks shows that same-sex couples raising children in states that ban gay marriage have nearly $9,000 less in annual household income than their married, opposite-sex counterparts.

"There are so many people who have suffered for decades without ever having health insurance, without ever having pension benefits," Codell says. The slow pace of justice "represents people dying off and never having been a family under the law."

A CLASH WITH RELIGIOUS FREEDOM

Even if the court strikes down the remaining state bans, however, it won't end the debate — or the legal battles. Up next: a collision course between gay rights and religious rites, in which churches and religious-affiliated groups seek exemptions from laws that follow the Supreme Court's decision.

"What statutory protections and exemptions should religious organizations seek to ensure their independence from state control and guard against retaliation?" a brief submitted to the court by Catholic, Baptist, Evangelical, Mormon and Lutheran organizations says. "What exactly are the rights of organizations and individuals with sincerely-held religious objections to participating in, facilitating, or recognizing same-sex marriage?"

To the ACLU's Esseks, the answers already are clear. "If we're talking about churches, churches get to do what they want," he says. "If we're talking about businesses, businesses have to follow the law."

Some on both sides of the debate say a peremptory ruling from the high court could mobilize the opposition in much the same way as the court's 1973 decision legalizing abortion has fueled state laws restricting that right.

"Do we want marriage to be the next Roe v. Wade?" says Carrie Severino, chief counsel at the conservative Judicial Crisis Network.

Smith predicts clashes over other gay rights issues, from equal access to employment to public accommodations. The question will be similar to this year's successful effort by employers with religious objections to avoid paying for their female employees' contraceptives, as well as failed efforts in Arizona, Kansas and elsewhere to exempt businesses from having to comply with civil rights laws for religious reasons..

"We have to figure out where to draw these lines," Smith says. "It is the last big battleground on which the whole issue of LGBT equality is going to be fought out."

And fight both sides will — potentially leading to still more Supreme Court showdowns.

"The last thing you can do is get off the field if you win," says Bonauto, who began the legal battle for gay marriage a generation ago. "I don't discount for a second that there are going to remain powerful voices against us."