Following the conclusion of oral arguments in Tuesday’s landmark U.S. Supreme Court hearing, advocates displayed cautious optimism that after years of legal wrangling, the U.S. legal system may finally support full marriage equality.

“The case for the freedom to marry shone through at every turn in the argument, undimmed and undeniable,” said Freedom to Marry founder and president Evan Wolfson following the hearing. He added that “it should be clear to a majority of justices, as it has been to a cascade of lower courts and a national majority for marriage, that there is simply no good reason, no just principle, no argument, no evidence to justify perpetuating marriage discrimination any longer.”

Though framed by supporters of same-sex marriage bans as an issue of states’ rights, arguments against marriage discrimination largely focused on the principle of equality.

“The choice is not between the Court and the State, but instead whether the individual can decide who to marry, or whether the government will decide for him,” said attorney Mary Bonauto, who argued in favor of marriage equality on behalf of petitioners in Question 1 in Obergefell v. Hodges, in her closing argument.

During the question period, the liberal bloc of the Court also voiced clear concern over the legal discrimination perpetuated by such bans.

Justice Stephen G. Breyer questioned the right of states to be able to exclude gay people from marriage. “Marriage is open to vast numbers of people,” Justice Breyer said, adding that same-sex couples “have no possibility to participate in that fundamental liberty. And so we ask, ‘Why?'”

The two potential “swing votes,” Chief Justice John Roberts and Justice Anthony Kennedy, both expressed ambivalence over what they saw as redefining the convention of marriage, which Kennedy said “has been with us for millennia.” However, Kennedy refuted claims that same-sex marriage harms conventional marriages or lacks the same “noble purpose.”

And Roberts, echoing the concerns of the liberal bloc, asked why marriage bans don’t amount to a “straightforward question of sexual discrimination?”

During the hearing, while marriage equality advocates rallied outside the courthouse, an anti-gay rights protester interrupted the proceedings, yelling that supporters would “burn in hell.” The individual was escorted out by security.

Though the Justices will reportedly vote on the decision later this week, a ruling is not expected until June. SCOTUS blog reporter Amy Howe says that there is “no clear indication” where Kennedy—and thus the rest of the Court—is headed.

Howe writes:

The Court has posted the full transcript and audio for Question 1 and the full transcript and audio for Question 2.

Marriage equality advocacy groups Freedom to Marry and Gay & Lesbian Advocates & Defenders (GLAD) both kept live blogs throughout the day’s proceedings.

Marking what advocates call “a significant legal and cultural moment for the country,” the U.S. Supreme Court will hear arguments Tuesday in Obergefell v. Hodges, the landmark gay marriage case that many legal experts believe will pave the way for full marriage equality in all 50 states.

The Court is reviewing a November 2014 decision from the 6th Circuit Court of Appeals, one of only three federal courts to uphold marriage discrimination since June 2013, the last time the Supreme Court heard arguments on marriage for same-sex couples.

Tuesday’s arguments will be divided into two parts:

  • The first will tackle whether the U.S. Constitution’s guarantees of due process and equal protection under the law cover a right to same-sex marriage.
  • The second concerns whether states must recognize same-sex marriages that take place out-of-state.

After more than two decades of litigation, a decision could determine whether gay men and women have a nationwide right to marry.

As Gay & Lesbian Advocates & Defenders (GLAD) put it, “The oral arguments mark a significant legal and cultural moment for the country, capping nearly twenty-five years of legal challenges, grassroots activism, legislative advocacy, and steady change in public opinion in favor of the freedom to marry for same-sex couples.”

Currently 37 of the 50 U.S. states and Washington, D.C. allow same-sex marriage. A recent poll by the Washington Post and ABC News found that a a record-high 6 in 10 Americans say they support same-sex marriage.

The Court is expected to rule by the end of June.