LGBT activists are reporting for duty as they face what many think could be their biggest threat since the AIDS crisis: A Trump-Pence presidency.

Donald Trump’s stunning victory last week set off a frenzied panic within the gay world, sending its most prominent activists into full-on battle mode.

“We’re all living in the upside-down,” longtime LGBT advocate Cathy Renna said, borrowing a famous phrase from the hit Netflix show “Stranger Things.” “That’s what it feels like, in 24 hours our world has changed.”

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Activists believe Trump is poised to erase decades worth of painstaking work, overturning President Obama’s executive actions, including the one he signed in 2014 prohibiting federal contractors from discriminating on the basis of sexual orientation and gender identity. Other LGBT protections at risk include those against discrimination in health care and government-sponsored housing.

Trump has also indicated that he would sign the First Amendment Defense Act, which would essentiality allow anti-gay discrimination in the name of “religious freedom.”

And of course the mother of all worries: The inevitable appointment of conservative Supreme Court justices, which could threaten every major pro-gay legislation, including same sex-marriage. On Trump’s shortlist: federal appeals court judge William H. Pryor, Jr., of Alabama, considered the “most demonstrably anti-gay judicial nominee in recent memory,” according to LGBT advocacy group Lambda Legal.

In 2003, when Pryor served as Alabama’s attorney general, he defended a Texas law criminalizing consensual gay sex, comparing gay rights to “prostitution, adultery, necrophilia, bestiality, possession of child pornography, and even incest and pedophilia.”

Transgender people, perhaps the most vulnerable subsection of the LGBT community, could be hit hardest. With Republicans in control of the House, Senate and the White House, Trump could roll back most of the community’s recent gains with little effort.

BuzzFeed’s Dominic Holden noted that Pence has already promised to withdraw federal guidance aimed at protecting transgender students, saying those issues are “best resolved at the state level.”

“This is the fight of our lives,” transgender activist Zoey Tur told TheWrap. “We have to re-litigate everything all over again.”

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Tur is already in the midst of forming a new advocacy group, The Resistance, and is now working with other activists to mobilize the LGBT community into action.

“When it became apparent Trump was going to win, I cried for the first time in years,” Tur said. “I was devastated. But then I dusted myself off, got out of the house and found something inside that I thought had long died: Passion.”

During his first post-election interview with “60 Minutes” on Sunday, Trump tried to reassure LGBT voters, telling CBS’ Leslie Stahl he was “fine” with the Supreme Court’s decision to legalize same-sex marriage, calling the matter “settled.”

But even that did little to calm fears within the LGBT community. Critics note that even if Trump does stand by his words, there’s still the much bigger issue of his running-mate Mike Pence.

As governor of Indiana, Pence signed a bill that would jail same-sex couples in his state for applying for marriage licenses. He also diverted funds from HIV prevention to so-called “conversion therapy treatments.” And, in perhaps his most headline-grabbing move, he backed a measure that allowed businesses to turn away gay and lesbian customers in the name of “religious freedom.”

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It’s impossible to tell what will happen once Trump and Pence are sworn in. But if history is any indication, underestimating the LGBT community’s power and organizational skills would be ill-advised.

In less than five decades, the gay community has been able to accomplish what few others minority groups have. The 1969 Stonewall riots spawned the gay liberation movement, and ACT UP — the AIDS Coalition To Unleash Power — helped force recognition of the AIDS crisis.

LGBT activists scored their greatest victory with the legalization of gay marriage last year — something many deemed unfathomable just years earlier.

The Los Angeles LGBT Center, the largest in the country, says it is already noticing the effects of a looming Trump presidency, citing an “influx of scared and worried people,” in a soon-to-be published editorial by its CEO Lorri Jean, obtained exclusively by TheWrap.

“Trump has contradicted himself repeatedly and lied constantly,” Jean writes. “But I have no doubt that there is going to be a serious consequence for the LGBT community.”

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Trump has made some overtures to the LGBT community on the campaign trail. During a national security address in New Hampshire in June, he told the audience he would be “a better friend” to the LGBT Americans than Hillary Clinton. And during his primetime Republican National Convention address in July, he surprised everyone when he proclaimed that, “As your president I will do everything in my power to protect LGBTQ citizens.”

But LGBT leaders point to the fact that it didn’t stop him from appointing Ken Blackwell, one of the LGBT community’s most vocal critics, to be in charge of his domestic policy. Blackwell is a senior fellow at the Family Research Council, one of the most anti-LGBT lobbying groups in the country. In 2006, when he ran for Ohio governor, Blackwell declared that homosexuality is a “lifestyle” that could be “changed.”

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Trump’s chief strategist, Steve Bannon, has used anti-LGBT slurs. In 2011, he said progressive women vilify conservative women because they aren’t “a bunch of dykes that came from the Seven Sisters schools up in New England.” When he worked at the conservative site Breitbart, it ran the headline, “WORLD HEALTH ORGANIZATION REPORT: TRANNIES 49X HIGHER HIV RATE.”

The fear over a Trump presidency is already being felt at the Trevor Project, a national 24-hour confidential suicide hotline for gay youths. It has seen an increase of 124 percent in calls since last Tuesday, a total of 668 calls or texts in less than week. For perspective, the center got about a third of that following the country’s deadliest mass shooting in Orlando’s gay nightclub, Pulse.

“I’m concerned,” Trevor Project’s spokesperson Steve Mendelssohn told TheWrap. “We’re seeing a dramatic increase in levels of stress and anxiety as a result if this election.”

According to a recent FBI report, hate crimes grew by 6.8 percent to a total of 5,850 incidents throughout 2015. While crimes against Muslims saw the highest spike (67 percent), hate crimes against Jewish, black and LGBTQ people all increased last year as well.

“It’s not a reality show anymore, it’s reality,” Renna said. “Donald Trump’s supporters have been unleashed.”