WASHINGTON — A Pentagon announcement that it will open military commissaries and child-care facilities this year to the same-sex partners of service members propels a wave of gay rights issues sweeping onto the national agenda.

Even as Defense Secretary Leon Panetta was announcing Monday the changes in military benefits, the Senate was debating a renewal of the Violence Against Women Act, which for the first time would extend federal protection to homosexual partners suffering domestic abuse. The Senate voted 78 to 22 Tuesday to renew the measure.

The White House is pressing Congress to grant immigration benefits to same-sex couples, and the Supreme Court is getting ready to hear a challenge to a 1996 federal law that defines marriage as solely a union between a man and a woman.

“Things are changing,” said Sen. Dianne Feinstein, D-Calif. “It’s slow, but it’s happening here. As states legalize same-sex marriage, I think this is having a remedial effect all around the nation.”

President Barack Obama elevated the cause of gay rights to the level of civil-rights struggles for blacks and women in his Jan. 21 inauguration speech.

“Our journey is not complete,” he said, “until our gay brothers and sisters are treated like anyone else under the law, for if we are truly created equal, then surely the love we commit to one another must be equal, as well.”

With polls showing public sentiment shifting toward acceptance of same-sex marriage, some Republicans are caught between the moderating social views of the country overall and the continuing opposition to the gay rights agenda by their party’s base of evangelicals and cultural traditionalists.

Republican Sen. Marco Rubio of Florida, one of his party’s potential 2016 presidential candidates, cautions that efforts to accept same-sex marriage could stall legislation.

“If that issue becomes a central issue in the debate, it’s going to endanger passage absolutely,” Rubio said of efforts to revamp immigration laws.

Regarding the sexual orientation language in the Senate version of the Violence Against Women Act, Rubio said “I wish we would have just reauthorized the existing law, which has broad and wide support.”

Public attitudes toward gay unions have shifted since Obama entered the Oval Office. Fifty-one percent of Americans now support same-sex marriage compared with 41 percent three years ago, according to NBC News/Wall Street Journal polls taken in December 2012 and October 2009.

Same-sex marriage was approved by voters in November in Maryland, Maine and Washington, the first time such unions were endorsed at the ballot box. Since same-sex marriages first were granted legal status by a Massachusetts court ruling in 2004, the unions have been authorized in Connecticut, Iowa, New Hampshire, Vermont and the District of Columbia.

“With respect to gay rights, we have seen the public come very far in their understanding that gays and lesbians should enjoy the same civil rights as anyone else,” Rep. Gwen Moore, D-Wis., said in an interview.

Moore is sponsoring a House bill reauthorizing the Violence Against Women Act that includes language to prohibit discrimination on the basis of sexual orientation and gender identity.

The military, which until 2011 prohibited gays from serving openly, will extend benefits such as child care, commissary privileges and transportation to military bases to same-sex partners by Aug. 31 and no later than Oct. 1, Panetta said in a memo.

Other benefits provided for spouses, including health care and housing allowances, remain barred because the Defense of Marriage Act, which prohibits federal recognition of gay marriage, continues to apply to the Defense Department, Panetta said.

The Obama administration opposes the law as unconstitutional. The Supreme Court is scheduled to hear the issue this term. The administration’s decision not to support the law left it to congressional Republicans, led by House Speaker John Boehner of Ohio, to spearhead its defense.

A Supreme Court ruling could alter the legal climate for gay couples and have significant tax consequences. Even when legally married in their home states, same-sex couples currently aren’t considered married for federal tax purposes — either for income or for estates — because of the current law.

“They will typically file joint returns for state purposes and separate returns for federal purposes, so obviously a lot more work,” said Theodore Seto, a tax professor at Loyola Law School in Los Angeles.

Because same-sex spouses aren’t treated as married for federal tax purposes, when one spouse dies assets don’t transfer to the survivor free of estate taxes. With heterosexual married couples, the estate tax is applied only upon the death of the second spouse.

The legislation the Senate voted on Tuesday includes a provision prohibiting discrimination against gays in grant programs for domestic violence victims.

Advocates say that explicit protections are necessary to clarify that programs serving gay and transgender victims are eligible to receive funds authorized under the law.

The name of the law, the Violence Against Women Act, can cause confusion particularly over the eligibility of services for gay men, said Sharon Stapel, executive director of the New York City Anti-Violence Project, an organization that advocates for services for gay victims of domestic violence.

Including non-discrimination language “gives everyone — legislators, service providers, grant administrators and the survivors of violence who are experiencing this violence every day — a clear message that they are included in this legislation and if they reach out for help, someone will be there to help them,” Stapel said in an interview.

Sen. Charles Grassley, R-Iowa, the top Republican on the Senate Judiciary panel with jurisdiction over the legislation, said he and party colleagues find the same-sex provisions “superfluous” because a 2005 reauthorization of the law included language prohibiting discrimination on the basis of religion, age and other criteria without specifying sexual orientation.

“The original legislation doesn’t allow discrimination of any kind anyway,” Grassley said in an interview.

Obama’s immigration proposal calls for foreign nationals in same-sex relationships to be treated the same as other couples when petitioning for spousal visas. Immigration coverage for gay couples wasn’t included in principles for a comprehensive overhaul released last month by a bipartisan group of senators.

Republican Sens. John McCain of Arizona and Lindsey Graham of South Carolina, who are among a bipartisan group of eight senators pushing for an immigration bill, have said that including same-sex marriage in the package would threaten a deal.

Rep. Jerrold Nadler, a New York Democrat who backs visas for gay partners, said in an interview that “keeping a loving couple apart” is “gratuitously cruel.”

There were an estimated 28,500 same-sex couples with one non-citizen partner in the U.S. in 2010, according to a 2011 study by the Williams Institute, a group at the University of California-Los Angeles that focuses on lesbian, gay, bisexual and transgender research.

Kathleen Hunter and Larry Liebert in Washington and Margaret Collins in New York contributed to this report.