WASHINGTON (CNN) -- Day two of the culture wars at the U.S. Supreme Court over same-sex marriage, and another opportunity for the justices to give political and legal clarity to a contentious issue.
The momentous week kicked off on Tuesday with arguments over California's same-sex marriage ban, and there was little indication when they concluded how the court might rule.
The stakes are high as the justices could, in one scenario, fundamentally alter how American law treats marriage with polls showing the public becoming more aware of the issue, and in some cases, more in favor of allowing gays and lesbians to legally wed.
This all further intensifies interest in Wednesday's arguments on the constitutionality of a federal law that, like California, defines marriage as only between a man and a woman.
But a practical impact of the 1996 Defense of Marriage Act means federal tax, Social Security, pension, and bankruptcy benefits, and family medical leave protections -- do not apply to gay and lesbian couples.
The appeal centers on that element and involves Edith "Edie" Windsor, who was forced to assume an estate tax bill much larger than other married couples would have to pay.
Because her decades-long partner was a woman, the federal government did not recognize the same-sex marriage in legal terms, even though their home state of New York did.
Obama opposes law, House to defend
The justices on Tuesday seemed to lack consensus on both jurisdictional and constitutional questions of the voter-approved California law, known as Proposition 8.
The federal statute also presents tricky gateway or "standing" questions that threaten to stall any final consideration of its constitutionality.
Those were expected to be the focus of much of Wednesday's arguments.
Led by President Barack Obama's recent political about-face on same-sex marriage, his administration opposes the Defense of Marriage Act.
Traditionally the solicitor general would defend the government's interest in a Supreme Court case. But Obama, who supports same-sex marriage, has already ordered the Justice Department to not take up the matter in court.
That raised the question of whether any party could rightfully step in and defend the law.
Besides the constitutional issue, the justices had specifically ordered both sides to argue a supplemental question: Whether congressional Republicans, operating officially as the Bipartisan Legal Advisory Group of the House, have "standing" or legal authority to make the case.
Lawyers representing the House GOP said that they should be able to take the lead, since both Windsor and the administration are taking the same legal position.
"Without the House's participation," said attorney Paul Clement, representing House leaders, "it is hard to see how there is any case or controversy here at all."
Windsor's legal team also said the House leaders could defend the law, at least partially, suggesting she wants resolution to the constitutional questions as soon as possible.
"I was devastated by the loss of the great love of my life, and I was also very sick, then had to deal with pulling together enough money to pay for the taxes," the 83-year-old Windsor told CNN recently.
The California case
The overriding legal question in the California case is whether the Constitution's guarantee of equal protection under the law prevents states from defining marriage as that state has done.
Some 80 minutes of arguments left no clear picture of how things might go.
The court could historically alter how the law treats marriage, striking down laws across the country banning same-sex marriage and matching an apparent cultural shift toward acceptance of same-sex couples.
Or it could leave the current patchwork of state laws in place, choosing to let state legislatures and state courts sort it all out.
"This was a deeply divided Supreme Court, and a court that seemed almost to be groping for an answer here," CNN Senior Legal Analyst Jeffrey Toobin said after the arguments.
Four of the more liberal justices seemed at least open to the idea that same-sex marriage should be allowed in California. Three of the more conservative justices seemed aligned with the view that it should only be for a man and a woman, and it's likely they'd be joined by Justice Clarence Thomas, who doesn't speak at arguments.
That could leave Justice Anthony Kennedy as, has often been the case, the swing vote.
While admitting the law's defenders are "not just any citizens," Kennedy raised concerns about whether just the possibility of same-sex marriage was enough to establish they had suffered harm -- a key jurisdictional hurdle allowing them to appeal in the first place.
A decision is not likely before June.
Andrew Pugno, general counsel for the Protect Marriage Coalition, the group defending Proposition 8, said its attorney had "credibly presented the winning case for marriage."
"We think the hearing went very well," he told reporters.
Attorneys representing the two couples seeking to overturn Proposition 8, meanwhile, said they couldn't tell how the court would rule.
"We are confident where the American people are going with this," said Theodore Olson. "We don't know for sure what the United States Supreme Court is going to do, but we're very, very grateful they listened, they heard, they asked hard questions, and there's no denying where the right is."
Nine states permit same-sex marriage
One of the plaintiff couples -- Paul Katami and Jeff Zarrillo of Burbank, California, who want to marry but can't because of Proposition 8 -- contend the state is discriminating against them because of their sexuality.
"This is about our freedom and our liberty," Katami said. "We are not trying to topple marriage. We are not trying to redefine marriage. What we are trying to say is that equality is the backbone of our country."
Forty-one states now forbid same-sex marriage, although nine of them allow civil partnerships. Nine other states allow same-sex marriage, and about 120,000 same-sex couples have gotten married, according to estimates.
Prohibitions seem to run counter to polls that show rising support overall for same-sex marriage.
A CNN/ORC International poll released on Monday found 53% of Americans now support same-sex marriage, up from 40% in 2007. As to how the federal government should handle the issue, another CNN/ORC International poll out Tuesday found 56% of the public feels the federal government should also legally recognize same-sex marriages.