The following editorial appeared in the San Jose Mercury News on Sunday, March 18:

When the U.S. Supreme Court agreed last year to take up Proposition 8, its ruling on California’s gay marriage ban was expected to be a turning point in the struggle for equal marriage rights.

But now that the time is near, a different truth is emerging: It almost doesn’t matter.

Like a Berlin Wall that once seemed impenetrable but ended up crumbling in a day, the conviction that marriage rights should be available only to straight couples is disintegrating before our eyes. When a U.S. president flips 180 degrees, as Barack Obama has done, and when conservative icons from Clint Eastwood to former Utah Gov. Jon Huntsman stand with him and with gay rights activists, you know it’s game over.

If the Supreme Court finds that the Constitutional guarantee of equal rights does not apply to marriage, public opinion will do the job. Polls show that California voters would handily support gay marriage today — young people tend to wonder what all the fuss is about — and nine other states already have legalized it.

The speed of this shift has been stunning. More than 130 moderate and conservative Republicans, including Eastwood, have signed a brief to the Supreme Court opposing Proposition 8. Meg Whitman, who supported Proposition 8 when she ran for governor in 2010, now opposes it. Just last week, Sen. Rob Portman, R-Ohio, a vocal opponent of gay marriage and adoptions, announced a change of heart: His son, a junior at Yale, had told his father he is gay.

The court will also hear arguments next week challenging the Defense of Marriage Act, signed by President Bill Clinton in 1996, which defines marriage as being between a man and a woman. Clinton now says he thinks DOMA is “incompatible with our Constitution” because it denies rights and benefits to gays and lesbians that are available to married couples.

A majority of Californians agrees. A February Field poll found that 61 percent approve of same-sex marriage, more than double the support when the question was first posed in 1977. National polls also are showing a majority in support for the first time. A recent Washington Post/ABC News survey found 51 percent in favor and 47 percent opposed to gay marriage.

Public opinion is unlikely to sway the Supreme Court, but Obama’s Justice Department has filed briefs against DOMA and Proposition 8. That’s unusual, and it’s hard to say how it will play. The justices have options that could maintain the legal status quo, make narrow changes or declare that limits on marriage rights are unconstitutional.

We supported gay marriage before DOMA and before Gavin Newsom shook up the status quo with his San Francisco weddings. We see no downside; society gains from the stability of committed families. Generations from now, gay marriage will be as accepted as interracial marriage, which once was illegal in much of this country.

The justices can’t stop this evolution, but they could accelerate it. We hope that’s what they do.