Conservative officials rushed to praise the change.
Lawmaker Pyotr Tolstoy said "this is a historic event, because our country has encroached on the most 'sacred' thing that exists in the liberal world."
In his latest homophobic diatribe on social media, Tolstoy called "LGBT" a "well-organized project to undermine traditional societies from within."
The Orthodox Church — headed by Putin ally Patriarch Kirill — welcomed the move.
"It's a form of moral self-defense of society," said Vakhtang Kipshidze, an official for the Moscow Patriarchate.
Well-known propagandist and pro-Kremlin TV host Vladimir Solovyov’s daughter, Yekaterina Solovyova, criticized the Supreme Court’s decision.
“International public movement LGBT has been declared extremist in Russia, meanwhile HAMAS gets official feasts at the Kremlin…. Basic human rights?” Solovyova wrote in an Instagram post published by the Ostorozhno Novosti news outlet.
In Muslim-majority Chechnya — ruled by Ramzan Kadyrov, who claims the region is exclusively heterosexual — officials also praised the move.
"Russia has shown once again that neither the collective West nor the United States will deprive us of the most important thing of all: a religious and national identity," said minister Akhmed Dudaev.
Miroshnikova said the federal ban will encourage harsher treatment of LGBT people in the North Caucasus.
“In general, the influence of federal lawmaking on the North Caucasus is strong,” she said. “They encourage violence by signifying that LGBT persons are undesirable and by refusing to investigate cases of homophobic violence. And these practices are spreading from, say, Chechnya. The latest decision will only accelerate this.”
The Russian government’s anti-LGBT actions are part of a broader ideology contrasting "traditional" Russian values with “Western” ones such as LGBT rights.
And while Russian officials claim to be “at war with the collective West” in Ukraine, any domestic social groups holding “Western” views must be fought as well.
Sergeyev, the St. Petersburg-based activist, linked the “extremist” designation to the upcoming presidential election in March, which will see the Kremlin work to rally the country around Putin as he runs for a fifth term in office.
“I believe this [the declaration of LGBT as extremists] is the government flexing its muscles before the elections. They’ll certainly put a lot of media weight on this to make sure the conservative electorate is watching the struggle for ‘traditional values.’ And LGBT people will be erased from the public sphere,” said Sergeyev.
“In the end,” Sergeyev warned, “the Russian prison environment is a particularly dangerous place for LGBT people.”