You hop a turnstile without paying. If you’re an immigrant in the country illegally or even a legal permanent resident, what happens next?

The question gets at the heart of the varying levels of immigrant protection that New York City can provide in the era of Donald Trump — levels which have potent political implications for Mayor Bill de Blasio.

In memos released this week, the Department of Homeland Security outlined how it would comply with Trump’s initial draconian executive orders about illegal immigration enforcement. Spoiler alert: The administration will, indeed, bulk up deportation forces. According to the order and memo, far more immigrants can be put on deportation notice, down to those who have committed offenses such as using a fake Social Security card.

Whether the federal government will have the requisite funding and manpower, cities like New York are preparing in earnest.

One level of reaction: that of de Blasio, who has trumpeted that New York City won’t cooperate with Immigration and Customs Enforcement requests to detain individuals. The exceptions are if ICE has warrants for individuals convicted of one of some 170 felonies in the last five years, or are on a terror watchlist.

The idea here is that the NYPD and city Department of Corrections will only be an active aid in the deportation process if someone is convicted of a felony or an apparent danger to society. ICE tested this idea last week, when its officers arrested a 19-year-old Salvadoran national who they said was a “self-admitted” MS-13 gang member. Yet his charges — which ICE said included fourth-degree criminal possession of a weapon, second-degree reckless endangerment, and disorderly conduct — did not rise to the city’s level of automatic cooperation. ICE arrested him last week without the city’s help.

The incident shows de Blasio sticking to his stated principles concerning detainer requests, but also underscores the limits of non-cooperation. Encouraged to focus on a wider swathe of immigrants here illegally post-executive order, ICE has a mandate to deport not just individuals on the margins of de Blasio’s offenders list but those far below it such as farebeaters.

Hopping that turnstile can lead to arrest and fingerprinting, which means your personal information is accessible by ICE agents to aid their own attempts to deport you — unless the city adds another level of protection for immigrants. City Council member Rory Lancman, for example, held a news conference Tuesday to urge the NYPD to use only existing civil violations for those who farebeat, which wouldn’t involve fingerprinting.

It’s part of a recent push in the City Council to shift to civil penalties for low level crimes — fines rather than jail time.

The de Blasio administration has resisted the blanket fare-beating idea, noting that officers already issue fines unless someone has an open arrest warrant, is in the act of committing another crime, or is a “transit recidivist.”

A “transit recidivist” is someone who has committed a recent crime in the subway or city at large. But you can also get that label if you commit three or more violations in the subway system over five years — like putting your foot up on the seat or farebeating — or simply being on parole or probation.

Sometimes this policy snaps up people who are legitimate dangers to public safety. But sometimes it simply ensnares those who committed infractions, who then get mired in a spiral of further and further penalties for a low-level offense.

That’s the argument of groups like End Broken Windows, who jumped onto the tail end of Lancman’s news conference on Tuesday and called for a further level of protection for NYC immigrants: not using arrests or even summonses for violations such as hopping a turnstile. Such critics argue that heavy policing of quality-of-life offenses falls onerously on immigrant and minority communities. Rather than harrying people with a legal system that can bring deportation, jail time, or even just expensive fines, they asked for positive investments: a subsidized MetroCard, for example, to low-income riders in order to forestall the impulse to jump.

De Blasio does not appear to be interested in that level of investment or those methods of shielding immigrants, Trump era or not. But those voices could grow at a moment when liberal New Yorkers are eager to do anything they can to oppose Trump’s immigration actions. Meanwhile, Thomas R. Decker, ICE’s NY enforcement field director says the mayor’s obstruction is “creating a potentially unsafe environment for its residents.” That could set the stage for its own showdowns if ICE activity increases.