The sad story:

Serve Donald Trump at your own risk. Being a top aide in his administration doesn’t usually work out well.

Some former advisers, like Michael Flynn, are in legal trouble. Others, like Sean Spicer and Anthony Scaramucci, became laughing stocks. Still others have tarnished once-sterling reputations.

Gary Cohn falls into the last category. Before working for Trump, Cohn had an underdog story good enough for a best-selling book. He overcame dyslexia, talked his way into a job at Goldman Sachs and rose to the No. 2 job at the firm.

Shortly after Trump’s election, Cohn accepted a job as the top White House economic adviser. He took it, everyone seems to understand, in the hope that Trump would later name him Federal Reserve chairman. That didn’t happen.

After Trump praised white supremacists last summer, Cohn offered a lukewarm criticism that managed to fall short of courageous while also infuriating his boss. Cohn was never again a leading candidate for the Fed job, which went instead to Jerome Powell, another former banker then serving not under Trump but as a Fed official.

Over the last 14 months, Cohn has served alongside Trump as the president has refused to defend the United States against Russian attacks; continued his string of racist insults; repeatedly tried to undermine the rule of law; and, to quote former President George W. Bush, trafficked in “outright fabrication.” None of this, evidently, stirred Cohn’s conscience enough to warrant resigning on principle.

Yesterday afternoon, he finally did announce his resignation. Quietly, other administration officials signaled that it was related — sort of — to Trump’s recent announcement of tariffs, a policy that Cohn opposes. Publicly, however, he was loyal to Trump.

For the rest of Gary Cohn’s career, whenever his name comes up, people will think of Donald Trump. The relationship worked out much better for Trump than for Cohn.

In The Times, the editorial board comments on Cohn’s departure. Elsewhere: Slate’s Jordan Weissmann notes that Cohn did have one big accomplishment in the job — the corporate tax cut he helped design. “Gary Cohn: The man who swallowed the president’s racism and personal humiliation in order to guide tax cuts for his old employer at Goldman Sachs, and then quit over some steel tariffs,” Weissmann writes.

I don’t know that he will be forever tarnished with the Trump brand. He was critical of Trump and unlike others, he left on principle. It is the ones who are still there and deal with him every day that will suffer long-term humiliation.

In early February, after President Trump’s well-received State of the Union address and Davos trip, economic adviser Gary Cohn was having lunch with the president and Chief of Staff John Kelly, in the small dining room off the Oval Office.

For a year, Cohn had felt like he was beating his head against a brick wall, leading Groundhog Day tutorials on the benefits of free trade and the danger of tariffs. After helping steer Trump’s victory on tax cuts, Cohn wanted another big assignment, commensurate with the skills, experience and appetite of a former president of Goldman Sachs. 
Advocating for Trump’s infrastructure plan, which is dead on the Hill, wasn’t juicy enough. Cohn said that if Trump could put him in a role where he would use 80% or 90% of his brain capacity, he’d stay. Otherwise, he should go.

“I’ve got to tell you. I’m working at like 20 percent of my capacity.”
— Gary Cohn to President Trump, according to West Wing sources

Then Trump announced this week that he planned to impose sweeping tariffs on steel and aluminum — an embarrassment to Cohn, who had boasted to his Wall Street and Hamptons buddies that he had kept the president on the right track on trade.

Cohn had planned to leave last week, according to the sources. But then with the departure announcements by Hope Hicks and Josh Raffel, Cohn didn’t want to pile on, the sources said. Yesterday — with the details of the tariffs plan up in the air, but with Cohn convinced Trump was going big — he told POTUS that he’d leave in coming weeks. Trump would be willing to entertain calling Cohn back for a big job (White House chief of staff?), and Cohn would consider it, the sources said.

Look, the Trump White House is bleeding talent, losing a half dozen or more officials who helped advise and contain the president. Worse, it is quite obvious there is little to no succession planning to quickly fill vacancies with top-flight talent.  This leaves the Trump White House understaffed and devoid of the moderating forces that helped shape his first 14 months in office. What remains is a more pliant, nationalistic staff, one much more aligned with Trump on trade, immigration and other issues.

One source close to the White House said: “POTUS rightly pointed out from the podium [yesterday] that he likes competition inside. They fight it out, he makes a decision. … What happens when the dissent is gone?”

So increasingly, the restraints are off. In this midterm year, and looking ahead to the reelection race, look for Trump to be more Trump — more Trump, The Nationalist.  Hardliner Stephen Miller’s influence may grow, on immigration and other issues. And now there’ll be one fewer Dem telling Trump to cool it on the culture wars.

There’s going to be a power vacuum in the West Wing. People will fill it — and they’re much more likely to be people who agree with Trump on trade and immigration than a person, like Cohn, who opposes him and is willing to tell the president to his face that he’s wrong.