The U.S. Senate on Monday confirmed Amy Coney Barrett to the U.S. Supreme Court.

The Senate confirmed Barrett with a 52-48 vote. Maine Senator Susan Collins was the only Republican to break ranks with her party and join Democrats, who were united in their opposition.

Barrett fills the vacancy left by Justice Ruth Bader Ginsburg, who died last month at the age of 87. Ginsburg played a pivotal role in cases that struck down state laws that criminalized gay sex (Lawrence), found same-sex couples have a constitutional right to marry (Obergefell), and expanded the definition of sex in federal law to include sexual orientation and gender identity (Bostock).

The Human Rights Campaign (HRC), the nation's largest LGBT rights advocate, criticized Monday's vote.

“Despite #AmyConeyBarrett's troubling record, Senate Republicans rushed through the fastest #SCOTUS confirmation process in modern history,” tweeted HRC Executive Director Alphonso David. “This was a power grab by Trump & these Senators – plain and simple. We must vote them out #WeDissent.”

During her confirmation hearing, Barrett refused to say whether two groundbreaking LGBT rights cases – Obergefell and Lawrence – were correctly decided, though she did give her opinion on Brown, which struck down state racial segregation laws in schools, and Loving, which put an end to state bans on interracial marriage.

In discussing the cases, Barrett said that she has never discriminated on the basis of “sexual preference.” Hawaii Senator Mazie Hirono, a Democrat, described the term sexual preference as “offensive and outdated” language “used by anti-LGBTQ activists to suggest that sexual orientation is a choice.” Barrett later apologized for using the term.

LGBT law group Lambda Legal and the National Center for Lesbian Rights (NCLR) also criticized Barrett's confirmation to the Supreme Court.

“This is a dark day for our justice system and American democracy,” Lambda Legal CEO Kevin Jennings said in a statement. “The Supreme Court of the United States, the court of last resort for justice in our country, should not be up for a power grab, but that is exactly what happened today. Amy Coney Barrett deeply alarmed us during her confirmation hearings when she refused to say whether she believed cases that are the backbone of the legal rights of LGBTQ people – such as Lambda Legal’s landmark case, Lawrence v. Texas, which decriminalized same-sex intimacy, and Obergefell v. Hodges, which legalized same-sex marriage – were correctly decided. We fear that all the progress we have made in recent years is now at risk.”

NCLR Executive Director Imani Rupert-Gordon said in a statement: “Today's action by the United States Senate is an affront to the American people and a threat to the credibility and integrity of the Supreme Court. Rushing this nomination through in the middle of a presidential election was fundamentally wrong and a travesty of the process of appointing Supreme Court justices. 60,000,000 Americans have already voted in this election. The voters who are choosing the next President should also be the ones to choose the future direction of the Supreme Court. As a result of today's action, five of the nine justices on the Court have been appointed by presidents who lost the popular vote. No matter who is the winner on Election Day, Congress must explore options for reforming the Court and protecting our democracy."

Barrett served as a trustee for three years at a religiously affiliated private school that effectively prohibited students with same-sex parents from admission, the AP reported.

In a statement released Monday before Barrett's confirmation, GLAAD President and CEO Sarah Kate Ellis called Barrett's impending confirmation “alarming for LGBTQ people.”

”Barrett’s time at a school that discriminated against LGBTQ families and hurt LGBTQ youth is disturbing and should disqualify her from the Court. Her stated views against marriage equality, rulings against access to abortion, and her public criticism of the Affordable Care Act are out of step with fair-minded Americans and threaten the progress our country has made to become a stronger and more equitable home for all,” Ellis said. “Her record against LGBTQ families and rights has no place in American life, let alone the highest court in the land.”

Barrett was sworn in to the Supreme Court at a White House ceremony Monday evening.