For all the moral turpitude, fake history, and agitated narcissism it placed on public display, the press conference that Donald Trump gave in the lobby of his gilded Fifth Avenue tower on Tuesday may ultimately serve a useful historical purpose. If nothing else, it clarified the ethical challenge that Trump’s Presidency presents to Americans of good will from all backgrounds and political persuasions: Who will stand against a man who described as “fine people” members of the crowd that marched through the streets of Charlottesville, Virginia, dressed in white, carrying torches, and chanting “Jews will not replace us”?

Since last November, many business leaders, and even the representatives of some labor groups, have coöperated with Trump on the grounds that he is the duly elected President, and they want their voices heard in the White House’s policymaking process. But, in terms of reputational risk and personal moral calculus, the price of accommodating Trump increased after his press conference. By openly giving succor to the likes of David Duke, the former Klansman, and Richard Spencer, the white nationalist who helped organize the “Unite the Right” hate gathering in Charlottesville, Trump now occupies a place in the political firmament where it is becoming almost as risky for corporate chieftains to associate with him as it is for them to distance themselves. On Wednesday afternoon, Trump disbanded two White House councils that were formed for C.E.O.s to give him economic and manufacturing advice, but the move is unlikely to end corporate America’s contradictory relationship Trump.

Even before Trump’s astonishing press conference on Tuesday, three business leaders withdrew from the manufacturing council in response to Trump’s refusal to condemn white supremacists and neo-Nazis in the immediate aftermath of Saturday’s violence, which culminated in one of the “Unite the Right” protesters, James Alex Fields, Jr., allegedly driving a car into a crowd of counter-protesters and killing Heather Heyer, a thirty-two-year-old paralegal from Charlottesville.

“I am resigning from the President’s American Manufacturing Council,” Kenneth C. Frazier, the chief executive of the drug company Merck, said in a statement on Monday morning. “America’s leaders must honor our fundamental values by clearly rejecting expressions of hatred, bigotry and group supremacy, which run counter to the American ideal that all people are created equal. As CEO of Merck and as a matter of personal conscience, I feel a responsibility to take a stand against intolerance and extremism.”

Frazier is one of the few African-American leaders of a Fortune 500 company. Having dragged himself up from the streets of North Philly, he is clearly someone who doesn’t shrink from challenges, and in calling out Trump’s woeful response in such direct language he displayed considerable courage. Given the financial risks involved in dealing with the government, the heads of big corporations generally shy away from anything that smacks of explicit involvement in politics, especially anything that would be likely to alienate a President. Frazier’s actions duly incurred the wrath of Trump, who lashed out at him in a tweet on Monday, but they also seemed to encourage a few other C.E.O.s to come forward.

On Monday evening, Brian Krzanich, the C.E.O. of Intel, the giant chip maker, and Kevin Plank, the boss of Under Armour, the trendy sportswear company, both announced that they were quitting the manufacturing council. The statements they issued were far weaker than Frazier’s, but the timing of their actions was unmistakable. On Tuesday morning, Scott Paul, the president of the Alliance for American Manufacturing, a trade group, quit the council, too, saying in a tweet, “it’s the right thing for me to do.”

In reverting to his initial claim that both sides were responsible for Saturday’s violence, Trump upped the ante for other members of the White House council who had equivocated in their initial responses. What, for example, did Jeff Immelt, the highly influential chairman of G.E., think of Trump’s press conference? On Monday, G.E. issued a statement saying the company “has no tolerance for hate, bigotry or racism, and we strongly condemn the violent extremism in Charlottesville over the weekend.” But the company also said, “it is important for G.E. to participate in the discussion on how to drive growth and productivity in the U.S. Therefore, Jeff Immelt will remain on the Presidential Committee on American Manufacturing while he is the chairman of GE.”

With his words and manner on Tuesday, Trump made it increasingly difficult for people like Immelt to fall back on the “business is business” justification for continuing to deal with him. Even before the latest verbal atrocities, Immelt and other C.E.O.s had encountered heavy flak online.

On Tuesday night, the leaders of the A.F.L.-C.I.O. resigned from the manufacturing council. “We cannot sit on a council for a president who tolerates bigotry and domestic terrorism,” Richard Trumka, the group’s president, and Thea Lee, the labor group’s deputy chief of staff, said in a statement. “President Trump’s remarks today repudiate his forced remarks yesterday about the KKK and neo-Nazis. We must resign on behalf of America’s working people, who reject all notions of legitimacy of these bigoted groups.”

At lunchtime on Wednesday, Campbell Soup’s C.E.O., Denise Morrison, announced that she, too, was quitting the manufacturing council. So did another C.E.O., Inge Thulin, of 3M, saying it was no longer “an effective vehicle” for promoting the values of “sustainability, diversity and inclusion” that he and his company supported. Finally, just after 1 P.M., Trump tweeted that he was disbanding both councils: “Rather than putting pressure on the businesspeople of the Manufacturing Council & Strategy & Policy Forum, I am ending both. Thank you all!”

Seven hours after Trump claimed that he disbanded the groups, the Wall Street Journal reported on Wednesday night that business executives, in fact, dissolved the councils, not Trump. During two conference calls Wednesday morning, a majority of C.E.O.s agreed to disband both councils. I.B.M.’s Ginni Rometty, Pepsi’s Indra Nooyi, Boston Consulting Group’s Rich Lesser, BlackRock’s Laurence Fink, and several other executives were prepared to resign on their own, according to anonymous sources who spoke to the Journal. Several other corporate bigwigs opposed the disbanding, including Boeing’s Jim McNerney. After the two calls, Blackstone Group’s chief, Stephen Schwarzman, called Trump’s son-in-law, Jared Kushner, and informed him of the executives’ decision. Minutes later, Trump tweeted that he had eliminated the groups. The Journal’s sources did not disclose the positions of each of the more than forty executives who served on the councils.

What stopped the corporate chiefs from going public with their opposition to Trump? Perhaps some of them privately agreed with some of the sentiments Trump expressed. More likely, they were still fearful of incurring his wrath and retribution. If this was the case, then, as Larry Summers, the former Treasury Secretary, noted in a withering blog post, “it is a damning indictment of the President and of their own cowardice.”

Summers ended his post by asking the C.E.O.s who hadn’t distanced themselves from Trump to wrestle with their consciences, and with Edmund Burke’s famous admonition that evil triumphs only when good men do nothing. The Jewish sage Hillel had an equally apposite quote: ”If not now, when?”

*This post has been updated to reflect the Wall Street Journal’s report on the disbanding of the Strategic and Policy Forum.