Setting the stage for a potentially historic ruling, the Supreme Court announced Friday it will decide whether same-sex couples have a right to marry everywhere in America under the Constitution.

The justices will take up gay-rights cases that ask them to declare for the entire nation that people can marry the partners of their choice, regardless of gender. The cases will be argued in April, and a decision is expected by late June.

Catholic bishops reacted strongly today, saying the decision “may be the most significant Court decision since the Court’s tragic 1973 Roe v. Wade decision making abortion a constitutional right.”

Archbishop Salvatore J. Cordileone of San Francisco, the bishops’ point man on marriage, asked in a statement, “To those arguing for a constitutional redefinition of marriage, one must ask: when did the Constitution suddenly mandate a novel and unfounded definition of marriage?”

The news comes on the heels of some of the pope’s strongest words against same-sex marriage.

Speaking to a group of Catholic families in the Philippines, the pope said, “The family is threatened by growing efforts on the part of some to redefine the very institution of marriage, by relativism, by the culture of the ephemeral, by a lack of openness to life.”

In October, bishops called the court’s decision not to reverse a lower court’s decision striking down bans on same-sex marriage in several states “extremely disappointing and surprising.”

“Millions of Americans had looked to the Court with hope that these unjust judicial decisions might be reversed. Instead, as a result of the Supreme Court’s action today, those decisions are allowed to take effect,” they said.

Ryan Anderson at the Heritage Foundation said voters should be allowed to decide the fate of same-sex marriage, not the courts.

“[T]he Supreme Court should not usurp the authority of the American people to discuss, debate and make marriage policy,” he wrote Friday.

Francis DeBernardo of the pro-gay Catholic group New Ways Ministry said most Catholics support same-sex marriage, and he expects that to continue regardless of the court’s decision.

“Even if the Supreme Court should decide negatively in this case, Catholic lay people will continue their work to make sure that their lesbian and gay friends and relatives receive equal treatment under the law,” he said.

The Catholic Church opposes same-sex marriage as well as other laws related to LGBT issues, such as workplace discrimination, and has struggled with rapid societal changes.

Gay employees at Catholic institutions have been fired for going public with marriage plans. The Archdiocese of Miami told employees earlier this month that they are prohibited from publicly supporting same-sex marriage and could be fired if they do.

Proponents of same-sex marriage said they expect the court to settle the matter once and for all with a decision that invalidates state provisions that define marriage as between a man and a woman. On the other side, advocates for traditional marriage want the court to let the political process play out, rather than have judges order states to allow same-sex couples to marry.

The swing vote remains Justice Anthony Kennedy, a Catholic, who has authored the last three major rulings advancing the cause of gay rights.

On one hand, he has defended voter-approved constitutional amendments, most recently in a Michigan case last year that upheld the state’s ban against racial preferences in university admissions. But he struck down the federal same-sex marriage ban as an affront to the constitutional rights of gays and lesbians.

Same-sex couples can marry in 36 states and the District of Columbia.

Material from the Associated Press and the Religion News Service was used in this report.