When Minnesota approves gay marriage, does Supreme Court listen? Maybe.

In the past two weeks the number of states recognizing same-sex marriages has risen from nine to 12, with new marriage bills signed into law in Rhode Island, Delaware, and – on Tuesday – in Minnesota.

Public polls in recent weeks confirm that more Americans than ever before accept the idea of same-sex marriage.

And there’s an even bigger potential prize on the horizon as the justices of the US Supreme Court work behind the scenes fashioning decisions expected next month in two major gay rights cases, both involving same-sex marriage.

While it is clear that gay-rights advocates are enjoying significant momentum and historic victories, it is not at all clear how these recent successes will be perceived by the justices at the high court.

Some analysts see the recent events as helpful to the cause of gay rights, while others suggest the rapid progress could convince a swing justice or justices that the intervention of the courts is not necessary.

In one possible scenario, the rising tide of public opinion and state laws favoring equal rights for gay men and lesbians may embolden Justice Anthony Kennedy, a potential swing vote, to join the court’s liberal wing in providing special legal protections for gay Americans like those that cover African-Americans, Latinos, and women.

On the other hand, the recent successes might also convince Justice Kennedy and/or other justices that the political process – and democracy itself – is an engine of change sufficient enough to guarantee the rights of gay Americans.

If gay-rights advocates have enough political clout to win legislative favor in three states within 12 days, perhaps they don’t need the intervention of the highest court in the land, according to this view.

In a key exchange during oral argument at the Supreme Court on March 27, Chief Justice John Roberts agreed that there had been a sea change in American attitudes about gay marriage in recent years.

“I suppose the sea change has a lot to do with the political force and effectiveness of people … supporting your side of the case,” the chief justice told a lawyer challenging the constitutionality of a ban on benefits to same-sex spouses under the federal Defense of Marriage Act.

The lawyer, Roberta Kaplan, rejected the contention that homosexuals in America are politically powerful.

“Really?” Chief Justice Roberts replied. “As far as I can tell, political figures are falling over themselves to endorse your side of the case.”

The comment was a reference to a number of members of Congress who announced their support of same-sex marriage on the eve of arguments at the high court.

Ms. Kaplan stood her ground. “No other group in recent history has been subjected to popular referenda to take away rights that have already been given or exclude those rights, the way gay people have,” she said.

“You just referred to a sea change in people’s understandings and values from 1996, when DOMA was enacted,” Roberts said. “And I’m just trying to see where that comes from, if not from the political effectiveness of groups on your side of the case.”

Kaplan responded: “I think it comes from a moral understanding today that gay people are no different, and that gay married couples’ relationships are not significantly different from relationships of straight married couples.”

What is unclear from the Roberts-Kaplan exchange is how it was likely viewed by Justice Kennedy, the potential deciding vote in the case.

If Kennedy agrees with Kaplan’s perspective, than the resulting decision may include sweeping federal protections for homosexuals.

If, on the other hand, Kennedy agrees with the chief justice that the gay community has become politically powerful and effective, then the resulting decision may minimize the role of the judiciary.

In his rebuttal argument in support of upholding the Defense of Marriage Act, former Solicitor General Paul Clement urged the justices to allow the political process to solve any problems with the law.

“The reason there has been a sea change is a combination of political power, as defined by this court’s cases as getting the attention of lawmakers, certainly they have that,” he said.

“But it’s also persuasion,” Mr. Clement said. “That’s what the democratic process requires. You have to persuade somebody you’re right.”

He added: “That’s going on across the country.”

Clement noted that Congress had repealed the "don’t ask, don’t tell" law barring openly gay individuals from the military. He urged the justices to “allow the democratic process to continue.”    

Despite the victories, the celebrations, and the thousands of marriages being planned for later this summer in Rhode Island, Delaware, and now Minnesota, there are still 31 other states with constitutional bans on same-sex marriages, and several others with statutes outlawing them.

Prior to signing Minnesota’s same-sex marriage bill into law, Gov. Mark Dayton looked out across thousands of cheering residents.

“What a day for Minnesota. And what a difference a year and an election can make in our state,” the governor said.

“Last year there were concerns that marriage equality would be banned here forever. Now my signature will make it legal in 2-1/2 months,” he said.

The new marriage law permits same-sex weddings starting August 1.

The unprecedented momentum began two weeks ago on May 2 when Rhode Island Gov. Lincoln Chafee signed that state’s same-sex marriage bill into law. The House had passed the measure 56 to 15, and the Senate approved it 26 to 12.

On May 7, five days later, Delaware Gov. Jack Markell endorsed his state’s same-sex marriage law. That bill passed the House 23 to 18, and the Senate 12 to 9.

The Minnesota measure passed the House 75 to 59, and the Senate 37 to 30.

In 2011, the Minnesota legislature passed a ban on same-sex marriages. Last November, voters in the state were asked to approve a constitutional amendment banning gay marriage. It was defeated 52 percent to 47 percent.