More telling than the handcuff fake-outs and fist salutes during Tuesday’s detention of several members of Congress for protesting in front of the Supreme Court was what Representative Alexandria Ocasio-Cortez and her progressive colleagues were wearing: green bandanas.

The green scarves have become such a common sight at abortion rights protests since the Supreme Court overturned Roe v. Wade that some news outlets have taken to calling it a “green wave.” On Tuesday, one congressman, Andy Levin of Michigan, even wore the bandana over his head like a do-rag. 

While the scarves have roots going back 20 years, to a feminist campaign for abortion rights in Argentina, their ubiquity on the streets of America can be traced back to one group in New York City, Rise Up 4 Abortion, which was founded by a group of communist adherents of a former 1960s-era radical named Bob Avakian.

Detractors of the group call it a personality cult, and claim it has wormed its way into a number of progressive causes over the years in order to foment a revolt against what the group’s website describes as the current “system of capitalism-imperialism that is founded on and perpetuates itself through cruel and literally life-stealing exploitation, murderous oppression, and massive destruction.”

Since it first appeared on the scene in January, Rise Up has emerged as the most militant of the abortion rights protest groups. It has paraded bound-and-gagged teenage girls in front of the homes of Supreme Court justices, disrupted church services, and staged raucous rallies in front of the court along the lines of what Ms. Ocasio-Cortez and her cohorts in The Squad got caught up in Tuesday.

As first reported by the Intercept last week, Rise Up was founded earlier this year by members of the Harlem-based Revolutionary Communist Party. Popularly known as the Revcomms, the group arose in the 1970s, with the help of Mr. Avakian, from the ashes of Students for a Democratic Society and other far-left political groups that emerged in the late 1960s.

The 79-year-old Mr. Avakian — hailed by his followers as “the most important political thinker and leader in the world today” — is a proponent of a so-called New Communism bent on bringing about a revolution in the United States. He once described the socialist societies of the Soviet Union and Maoist China as “an unprecedented and inspiring breakthrough in liberation for humanity.”

Throughout the 1980s and 1990s, Mr. Avakian and his cohorts staged May Day rallies around the United States and helped organize Maoist factions in the developing world such as the Sendero Luminoso in Peru and rebels in Colombia that eventually became full-fledged insurgencies fighting to overthrow their respective governments.

In the decade beginning in 2010, the group began making more waves at home, burning flags outside national political conventions and adopting the struggle against racial injustice and heavy-handed police tactics as their own. President Trump’s election in 2016 sent them into overdrive. Vice President Pence was described — by one of the group’s leaders, Sunsana Taylor, in an appearance on Fox News’s Tucker Carlson show — as a “Christian fascist theocrat”; and Mr. Trump was called “worse than Hitler.”.

Ms. Taylor’s latest project is Rise Up 4 Abortion. The Intercept placed her outside the Supreme Court with a megaphone and trademark green bandana at a rally in late June where Ms. Ocasio-Cortez was lured to the megaphone to loudly declare the Supreme Court “illegitimate” and beseech supporters to take to the streets in protest. By then, Ms. Ocasio-Cortez was also sporting a green scarf.

Longtime activists for abortion rights are not happy that Mr. Avakian and his revolutionaries are sucking up oxygen in the movement. Rise Up’s flashy protests, such as the stunts in front of the homes of the justices, and its earnest young activists are getting much of the media attention — and therefore the donations — that might otherwise go to more impactful efforts, they say.  

After some Rise Up activists disrupted a service at Joel Osteen’s mega-church in Houston by stripping down to their underwear and shouting obscenities, a writer and feminist activist from Austin, Texas, Andrea Grimes, begged reporters to stop giving the group any exposure.

“These folks are part of a widely despised cult of personality not tied to any serious repro health, rights, or justice organization,” Ms. Grimes said on Twitter. “They are not supported by folks here doing the work on the ground. Nobody knows them. Nobody likes them. They’re not a thing. They show up when the cameras come on.”

Following the criticism leveled against them, the leaders of Rise Up posted a statement on the group’s website denouncing the “scurrilous, dishonest and highly destructive and divisive attacks” against it.

“At a time when fascists in this country are not only making but carrying out all kinds of threats of violence against people who are resisting them, these attacks endanger these leaders, and should remind decent people of the kind of attacks and distancing that cost lives in the 1960’s,” the statement said.

The statement assured supporters that any money raised by Rise Up has been used for precisely the purpose for which those funds were raised. That purpose was left unsaid in the statement, though it did direct readers to the website of the Revolutionary Community Party, where a pop-up tells browsers: “Now is the time to learn about and rally to Bob Avakian. Donate to this site to enable thousands and then millions to connect with this revolutionary leader and what he has to say.”

As of July 18, $3,948 had been raised out of a goal of $20,000.