(CNN) Calls to eliminate the Immigration and Customs Enforcement agency, for years relegated to the far-left corners of progressive activism, have been thrust this week into the mainstream of Democratic politics.

Cracks in the dam became visible 10 days ago , when a group of demonstrators confronted Homeland Security Secretary Kirstjen Nielsen at a Mexican restaurant in Washington. They called for an end to the Trump administration policy that resulted in separating migrant families at the border and, as the viral protest heated up, began to chant: "Abolish ICE!"

Less than two weeks on, the demand -- a favored meme on the left -- has gone from a progressive fringe cause, mostly ignored even by some of the most liberal lawmakers, to a political message being embraced by a growing roster of influential national Democrats.

Fueling its sudden ascent have been a series of recent shocks to the system. On Tuesday, US House candidate Alexandria Ocasio-Cortez delivered a stunning Democratic primary upset in New York after campaigning on abolishing the agency, which was formed in 2003 as part of a post-9/11 federal overhaul that created the Department of Homeland Security.

Two days after Ocasio-Cortez's primary, New York's Kirsten Gillibrand became the first senator and potential 2020 candidate to announce her support for the agency's elimination. Less than 12 hours later, on Friday morning, New York Mayor Bill de Blasio joined the chorus , telling WNYC's Brian Lehrer, "ICE's time has come and gone."

"I don't think ICE today is working as intended," Gillibrand said Thursday night on CNN's "Cuomo PrimeTime." "I believe that it has become a deportation force, and I think you should separate the criminal justice from the immigration issues."

Thank you, @NYCMayor, for joining the call that seems the separation of children and violation of human rights as an inexcusable bright red line in the United States of America. https://t.co/5Dwxq0XJ9T — Alexandria Ocasio-Cortez (@Ocasio2018) June 29, 2018

In a Facebook post on Saturday, Massachusetts Sen. Elizabeth Warren wrote, "The President's deeply immoral actions have made it obvious that we need to rebuild our immigration system from top to bottom, starting by replacing ICE with something that reflects our values," a line that mirrored her statements in a speech at a protest in Boston.

The rapid escalation was years in the making.

Progressive immigration rights activists -- during both Republican and Democratic administrations -- have come to view ICE as a rogue agency that terrorized immigrant communities. Calls for its dissolution, once rare, are spreading.

A group of 19 agents with its Homeland Security Investigations unit, which deals with complex investigations including transnational crime, recently wrote a letter to Nielsen asking her to break up the agency amid what they described as a debilitating conflation of their work with ICE's deportation activities. Concerns over the public backlash to actions by the Enforcement and Removal Operations division were, they wrote, making HSI's work impossible.

In their message -- first reported by The Texas Observer -- the agents reported that some jurisdictions had agreed only to "partner with HSI as long the 'ICE' name is excluded from any public-facing information."

On Capitol Hill, Rep. Mark Pocan of Wisconsin is now working with fellow Democratic Reps. Pramila Jayapal of Washington state and Adriano Espaillat of New York on legislation to eliminate the agency.

In an interview, Pocan said a recent series of aggressive actions by ICE had led him to conclude that it was effectively serving as President Donald Trump's "own political police force" -- a tool for creating a sense of crisis to help build support for a border wall and other hardline immigration policies.

For Pocan, Trump's call on Sunday to return immigrants who enter the country illegally without judicial proceedings was the last straw.

"The culmination of all those things, going to the border and then when the President started talking about getting rid of due process, was it," he said. "You're just kind of like, all right, this has gone way astray, and we need to start over."

But there is dissent now in the Democratic ranks.

Leading progressives, like Vermont Sen. Bernie Sanders and -- until Saturday -- Warren, have stopped short of calling for ICE to be terminated outright and the Congressional Hispanic Caucus has circulated talking points advising caution -- arguing in a memo obtained by CNN that "abolishing ICE without changing President Trump's disastrous immigration policy will not solve the problem." They're not alone. Some progressives on the Hill worry that wielding the "Abolish ICE" banner would be a political gift to Trump and his allies, and that Democrats should consider a more nuanced approach.

Republicans are casting progressive calls to abolish the agency and the recent momentum in the Democratic Party as a move to the far left, evidence that Democrats are weak on border security and immigration enforcement.

"Recent calls to abolish ICE are dangerously misguided," agency spokeswoman Jennifer D. Elzea said in an email. "Instead of being insulted with politically-motivated attacks, the men and women of ICE should be praised for risking life and limb every day in the name of national security and public safety."

Activists and progressive leaders are pressing on, becoming more aggressive in their push to abolish the agency, an effort many in the movement view as both a way to open up the debate over decades of bipartisan US immigration policy and, crucially, win elections.

"The Democratic Party had a reckoning about the crime bill, financial deregulation and about welfare reform, but it never really had a reckoning about their complicity in creating both the intellectual framework for this sort of policy," said Sean McElwee, a leading activist in the anti-ICE movement and early supporter of Ocasio-Cortez's campaign. He cited the 28-year-old Democratic socialist's unapologetic embrace of the issue as a key factor in her Tuesday triumph.

"She had an actual campaign strategy that revolved around ICE, and it was very smart, because (incumbent Rep. Joe) Crowley was weak on immigration and she knew that he would never be able to get where he needed to be to win that primary," McElwee said. "So she just hammered him on it. She didn't shy away from saying it. She put it in her ads. She ran on the issue. She challenged him in the debate. I think 'Abolish ICE' is where it is today because of her leadership."

Efforts to further escalate the fight beyond the electoral realm are already in motion. The Democratic Socialists of America, which reported its largest spike in new, dues-paying members since Trump's election on the day after Ocasio-Cortez's win, are planning a national campaign to ramp up the pressure.

Love when someone comes to their very first DSA meeting and is willing to jump right in with their art talents 🎨 pic.twitter.com/KrLOaF75KT — Kristin P. 🌹⚑ (@donaisabelle) June 29, 2018

Maria Svart, the group's national director, said the organization is ready to "apply pressure wherever possible to lift up the narrative that ICE is horrific, has no place in our communities and needs to be abolished."

"That looks different in different places," she said. "We have chapters in every state in the country, and folks are doing everything from vigils to encampment to bird-dogging to really raise this issue in the public eye and say, 'We do not submit to this.' "

Protests have already begun to grow in size and frequency. By Friday afternoon, police in Philadelphia had made six arrests outside the city's ICE office amid a heated demonstration, as crowds chanted, "I'd rather go to jail than go to a detention center."

Philadelphia City Council member Helen Gym recorded and tweeted out video of the scenes.

"I'd rather to go to jail than go to a detention center." @NationalADAPT Tony's emotional response before getting arrested becomes a group chant outside ICE. #AbolishICE pic.twitter.com/NwHXbBJ6cw — Helen Gym (@HelenGymAtLarge) June 29, 2018

Activists are also seeking to expand the moral dimension of the fight. Hartford City Councilwoman Wildaliz Bermudez, of the Working Families Party, said the visceral nature of reporting from the border during the height of the family separation crisis pushed the movement toward a tipping point.

She likened the situation to what followed the white supremacist rallies last summer in Charlottesville, Virginia.

"It has to be a unified front (in response to ICE)," Bermudez said, "because like when you have people chanting on the street, 'You will not replace us,' they're not just talking about Jews. They're talking about everyone."