WASHINGTON — Fueled by outrage over the Trump administration's immigration policies, a small but growing number of progressive Democratic candidates are signing onto a nascent effort to abolish Immigration and Customs Enforcement (ICE).

It’s a radical idea and one that was confined to the fringes just months ago in a party that has historically balanced calls for better treatment of migrants with support for stronger border security and enforcement.

But as an emboldened left challenges old assumptions about everything from health care to jobs, doing away with ICE has become the latest issue left-wing insurgents can use to differentiate themselves from more established rivals in Democratic primaries, especially as mainstream party candidates increasingly co-opt other contrast issues, like Medicare for All and a $15 minimum wage.

This week, as the crisis at the border intensified and dominated headlines, mentions of abolishing ICE shot up on Google searches and Twitter as new candidates and activists groups jumped onto the bandwagon.

And the protesters who disrupted Homeland Security Secretary Kirstjen Nielsen's dinner at a Mexican restaurant this week in Washington yelled "abolish ICE!" and other slogans as they drove her from the eatery.

"I think we've come to a moment where we need to call for the abolishment of ICE," actress Cynthia Nixon, who is challenging New York Gov. Andrew Cuomo in next week's Democratic primary, told an audience in Brooklyn on Tuesday, while acknowledging that governors have little influence over the federal agency.

Also in New York, at least three progressives challenging incumbent members of Congress have used the issue to differentiate themselves ahead of Tuesday's vote.

The insurgents are not favored to win, but they've made waves and take credit for forcing the incumbents — including Rep. Joe Crowley, who is in line to potentially succeed Rep. Nancy Pelosi of California as the party’s leader — to move to the left on the issue.

Meanwhile, Florida Democrat Matt Haggman ‏just a launched a TV ad entirely focused on his desire to "close ICE down." He goes on use that position to contrast himself with Donna Shalala, the Bill Clinton Cabinet official who is currently the front-running Democrat in the heavily Hispanic district.

Also on board is Randy Bryce, the mustachioed ironworker who is running with the official blessing of the Democratic Congressional Campaign Committee in House Speaker Paul Ryan's Wisconsin district.

Deb Halaand, who would be the first Native American woman in Congress, won a primary in a safe Democratic district in New Mexico this month on a platform that included the policy.

Overall, 15 Democratic congressional candidates are currently running on de-funding or abolishing ICE, according to Sean McElwee, a New York-based activist who has helped lead the charge.

That not a huge number in a field that includes hundreds of candidates across the country. But the idea seems to be gaining steam quickly considering that until earlier this year "it was just a thing that me and some people yelled about on Twitter," McElwee said.

"Trump's boorishness has exposed the fundamental inhumanity of the system for Democrats in a way that they were never going to see when Obama was president,” he said.

Activists like McElwee favor returning to a system like the one that predated ICE's creation as part of the Department of Homeland Security under President George W. Bush. They'd like to see immigration enforcement handled by the Department of Justice, not DHS, which they say invites abuse because undocumented immigrants are seen as a national security threat.

But McElwee acknowledges the idea is as much about expanding the window of possibilities on overhauling the immigration system as it is about specific policy goals.

Cecilia Muñoz, a top policy adviser to the Obama White House on immigration and other issues, thinks the approach is misguided.

"I understand where it comes from, and I understand the community's hatred of this law enforcement organization," she said in a recent interview with a Slate podcast. "But at the end of the day, as a policy goal, I don't think abolishing ICE is realistic. I also think the argument has the effect, has the potential to push away folks who ultimately we need on our side in order to make the kinds of reforms in the way ICE behaves and in the immigration laws themselves."

Suraj Patel, an Obama alum who is challenging Rep. Carolyn Maloney, D-N.Y., in Tuesday's primary, is unconvinced by those calling for caution.

"We're crazy if we think that, after 25 years of them rolling us on this issue, they're going to come on board," he said of Republicans.

Patel says he brings up abolishing ICE at every town hall meeting he hosts, as well as in multiple op-eds he's written and a recent video he recorded in Spanish.

"We really hung our hat on this,” he said. "It's emblematic of what I mean when I say we don't need just more Democrats, we need better Democrats."