It took steel to break a man’s heart in the White House.

Finally, in an administration wracked with crisis, turmoil and turnover, one man took a lonely stand on principle.

Gary Cohn, chief economic adviser to President Donald Trump, is resigning in protest over Trump’s tariffs on steel and aluminum. That passes for an act of conscience for free trade believers in this crowd.

Tip your hat to Wall Street’s man, who delivered corporations a major tax break. Cohn’s work is done. What a sorry excuse for a Democrat. In fact, his departure is causing heartburn among Republican leaders.

Cohn’s exit is notable for only one thing. It begs the question of why it took so long for a top White House official to admit they can’t brook this anymore and walk with hands washed and head high.

As the air cleared after the deadly Charlottesville, Va., race riot last summer, Trump proclaimed there were “very fine people” on both sides. It was the most egregious moment of his presidency. Yet not a single soul resigned — it was like the dog that didn’t bark in the Sherlock Holmes mystery. Tough John Kelly, then the new White House chief of staff, listened to the tirade without batting an eye.

Recently, Trump used a vulgar phrase to describe certain countries in an immigration meeting with lawmakers. When that went public, Sen. Cory Booker, D-N.J., raged at new Homeland Security Secretary Kirstjen Nielsen, calling her “complicit” at a hearing. She did not apologize for the boss’ ugly remark. Secretary of State Rex Tillerson let it pass.

And since then, Trump has proven to be a nightmare for “Dreamers,” immigrants who came to America as children.

Think back to the “Saturday Night Massacre,” when President Richard Nixon’s attorney general, Elliot Richardson, and the deputy attorney general, William Ruckelshaus, each refused Nixon’s desire to fire special prosecutor Archibald Cox. They resigned instead, showing moral courage. I was a child, and that was a lesson in standing up to a president of one’s own party.

In the tawdry Trump era, the hero count is zero.

James Comey, the self-righteous FBI director, was fired by Trump last spring. He poses as a martyr and truth-teller, but don’t fall for that line. Comey made grave mistakes that hurt the 2016 election on the Russian and Hillary Clinton fronts. He was far from an exemplary director. But he wasn’t too proud to serve Trump. I’d have more respect for him if he had resigned.

Sordid Steve Bannon, Trump’s chief strategist, was forced out in the wake of Charlottesville, as an outspoken “white nationalist” confederate. On Trump’s first day in office, the Rev. Jesse Jackson told me to beware the second coming of the Confederacy.

White House communications director Hope Hicks, Trump’s favorite staffer, is leaving, but not in protest. Hicks, 29, was scalded in the public eye by her romance with Rob Porter, 40, recently the staff secretary. He left in disgrace after his alleged abuse of two ex-wives surfaced — not one, but two. Still, Trump and Kelly looked on Porter favorably, sorry to see him go.

In a White House plagued by a 43 percent turnover rate, shady characters and a special counsel’s Russian investigation — not to mention Stormy Daniels — it’s truly remarkable that so many men (and a few women) furthered the cruel Trump presidency without expressing moral qualms.

The seeds were sown with the Muslim ban on travel, overthrown by courts. Nobody said boo.

White House counsel Don McGahn is my favorite coward from early on. Sally Yates, acting attorney general, urgently told him that new national security adviser Michael Flynn could be blackmailed by Russia. He was a clear and present danger. McGahn did not heed her warning.

Flynn has since pleaded guilty in special counsel Robert Mueller’s Russian investigation. McGahn may show some backbone yet.

Hapless Sean Spicer, the first White House press secretary, lied to reporters on the first day about the inauguration turnout. He was a bystander in Trump’s war on the news media.

You’ve got to give Trump this: he knows how to pick ’em.

Jamie Stiehm writes about politics, culture and history as a weekly Creators Syndicate columnist and regular contributor to U.S. News & World Report. Follow her on Twitter: @jamiestiehm. Click here to read previous columns. The opinions expressed are her own.