So many people have staggered away from Donald Trump’s smoking wreckage, via resignation or removal, that it’s tempting to employ black humor — to quip, for instance, that Homeland Security Secretary Kirstjen Nielsen quit because she wants to spend more time caging her family.

But willfully separating migrant children from their parents, and losing track of how many separated children are still being victimized, is no joking matter. Nielsen will forever be known as the face of the Trump regime’s border brutality. And last spring, even as the regime’s human rights abuses were in full swing, she had the temerity to deny that they were even happening. In her Orwellian words, “We do not have a policy of separating families at the border. Period.”

Still — and this is the broader point that needs to be made — Nielsen deserves a scintilla of sympathy. She was working for a guy who irrevocably soils whoever serves in his amoral orbit.

Nielsen fell out of favor with Trump because she was deemed to be insufficiently brutal about the border, because it was ultimately impossible to sate his every whim. That is not a surprise; Tom Ridge, the ex-Pennsylvania governor and first Homeland Security secretary, said last June that “this president, with some of the things he sometimes does and says, has made her job harder.” And according to a senior administration official, who spilled the beans to CNN yesterday, Nielsen “believed the situation was becoming untenable, with the president becoming increasingly unhinged about the border crisis and making unreasonable and even impossible requests.”

Yes, folks, we’ve reached the point where even sources inside the regime are using the word “unhinged.”

When Nielsen was first tapped in 2017 to become Homeland secretary, Trump hailed her with his usual superlatives, called her “tremendously qualified.” In 2018, when she was defending the child-separation policy that she said did not exist, Trump declared that she was doing a “fabulous” job and a “great” job.

But, as the point person for Trump’s most obsessive issue, Nielsen got targeted by both sides. She took the heat when the separation policy earned worldwide condemnation, but took increasing heat fromTrump hardliners (Stephen Miller, John Bolton) who viewed her as soft on migrants. Indeed, when Trump recently voiced his desire to reinstate the family-separation policy (which he abolished last June via executive order), Nielsen imperiled herself by pointing out that the federal courts barred him from doing it.

What a thankless job she had. One of her first experiences was attending the January 2018 meeting where Trump made his racist remark about “s-hole countries.” She didn’t want to confirm that she heard it, but she didn’t want to deny it, either. So she said: “I don’t recall him saying the exact phrase” — a statement with enough wiggle room to accommodate an 18-wheeler. The soiling of her soul had begun.

Perhaps her original sin was working for Trump in the first place. Surely she understood — with a warning from John Kelly, her mentor — that amoral servitude would be her fate. But Nielsen wouldn’t be the first person to take a top job in the hope that she could make things a little bit better. Foolish naivete, yes. She picked a side, and history will rightly judge her harshly.

She stayed long enough to become fully complicit. Like most aides in high places, she eschewed the option of resigning on a point of principle. That rarely happens in Washington. One notable exception is Walter Shaub, the ex-director of the federal Office of Government Ethics, who quit his job six months after Trump took office because he couldn’t abide Trump’s trampling of ethics and norms. He later told me, “I felt that staying on the job would make me complicit. If I stayed, I feared that I would be window dressing for corruption.”

Nielsen has been soiled by her servitude, but this is ultimately a story about Trump, who intends to replace her with someone who, in his lingo, is “stronger.” It speaks volumes about this twisted regime that an official who put kids in cages is deemed to be insufficiently extreme.

Nielsen was bad, but it’s even darker at the bottom of the barrel.

Dick Polman is the national political columnist at WHYY in Philadelphia and a “Writer in Residence” at the University of Pennsylvania. Email him at dickpolman7@gmail.com.