By Arianne de Vogue

Quiet has returned to the Supreme Court. For now.

The plaza has been swept clear of debris from the same-sex marriage demonstrations that took place earlier in the week. Sleeping bags — left behind by those who spent nights on the sidewalk, hoping for a seat at the historic oral arguments — have been removed. The chanting between dueling sides of the debate is just a faint echo.

The case has been made over whether states are required to license same-sex marriages and recognize those nuptials performed in other jurisdictions. Now it’s up to the justices.

If tradition holds, they will gather in the court’s conference room on Friday to discuss and possibly cast an initial vote on one of the most historic cases to come before the Roberts Court. At conference, Chief Justice John Roberts leads off the discussion, and then one by one, in order of seniority, the justices are likely to reveal how they intend to vote. The court won’t confirm the subject of a particular conference, but typically the Friday conference of an argument week is devoted to the cases heard the previous Tuesday and Wednesday.

The golden rule at conference is that no one is allowed to speak twice until every justice has spoken once. Justice Elena Kagan, the court’s junior member, will go last, and she is also charged with answering the door if a law clerk or staff member were to send a message. Only justices are allowed in the room, and for a period of time, they alone will know the likely outcome of the case brought by 14 couples and two widowers who hope to clear the way for same-sex couples to marry nationwide.

In an interview with C-SPAN in 2009, Justice Anthony Kennedy, whose vote will most likely be crucial in the same-sex marriage case, spoke about the court’s conferences and admitted to being nervous going in.

“It’s like being an attorney once again,” he said, referring to the process of presenting his position. “As we go around the table, it can be quite fascinating to see how the case is unfolding.”

He added that the atmosphere can be tense if the court is closely divided.

“If a case is close, 5-4, and let’s say you are on the side that prevailed with the majority, there are not a lot of high fives and back slaps. There is a moment of quiet, a moment of respect, maybe even awe at the process. We realize that one of us is going to have to write out a decision which teaches and gives reasons for what we do. ”

The same-sex marriage arguments that occurred on Tuesday lasted for two and a half hours. The justices shot dozens of questions at a total of five different lawyers.

The next day, during oral arguments in Glossip v. Gross, a case over lethal injection, the justices seemed unusually irritable, cutting each other off and interrupting the lawyers. It was, perhaps, a sign of fatigue.

At one point, Roberts referenced the interruptions and suggested that the justices were not letting the lawyers make their case.

“To an extent, that’s unusual, even in this court,” Roberts told a lawyer with a hint of irritation. “You have been listening rather than talking.”

He granted the advocate more time, adding, “Hopefully, we’ll have a chance to hear what you have to say.”

By Thursday, same-sex marriage advocates around Washington were left to speculate about whether the court was swayed toward their cause.

Some were clearly concerned by the opening few minutes. They had entered the chamber full of optimism based on the fact that Justice Anthony Kennedy has already written three opinions in favor of expanding same-sex rights.

But that optimism faded as Kennedy joined with other conservatives in expressing some skepticism about changing the definition of marriage.

“This definition has been with us for millennia,” Kennedy said.

“He succeeded in making everybody feel less than certain,” said Paul M. Smith, a lawyer from Jenner & Block who argued and won a key gay rights case in 2003 and is considered one of the most knowledgeable advocates on the issue in the country.

But Smith, speaking at an event hosted by the Constitutional Accountability Center, was quick to add that he felt that as the argument wore on, Kennedy’s questions caused optimism to return to those who want the court to strike down state bans on same-sex marriage.

For now, oral arguments are over for the term, and the justices will race to finish drafting opinions by the last week of June and then begin their summer break.

In 2012, after stunning conservatives by voting to uphold Obamacare, Roberts was scheduled to travel to Malta. Before leaving, he made a joke that referenced the pressure the justices feel at the end of a big term.

“Malta, as you know, is an impregnable island fortress,” he said, according to The Associated Press. “It seemed like a good idea.”