Trump on Monday eventually bowed to pressure and denounced racist hate groups, but the damage was done. Frazier and his compatriots joined the ranks of Elon Musk of Tesla, Bob Iger of Walt Disney and Travis Kalanick of Uber Technologies -- executives who walked away from business panels Trump touted, taking the unusual steps of publicly distancing themselves from a sitting president.
"The value of the advisory council goes down when respected members leave over issues of principle," said James Post, professor of management emeritus for the Questrom School of Business at Boston University.
"Whereas the president could have claimed to learn from the council, now it seems that he only listens when they agree with his opinion."
Frazier's departure earned angry tweets from Trump, with one making an all-caps jab about costly prescription drugs and another griping that Merck is a leader in high prices and in sending jobs overseas.
Plank, who issued his resignation Monday evening, came under fire earlier this year from Under Armour brand ambassadors, including Golden State Warriors point guard Stephen Curry, for comments the CEO made about Trump being a pro-business asset in the White House. Some of the white supremacists in Charlottesville were photographed in Under Armour apparel, a fact noted in posts on the company's Twitter page Monday, which was crowded with calls for a product boycott if Plank didn't resign from the council.
As for Intel's Krzanich, his Twitter account was peppered Monday by pleas for him to quit the White House group after he posted that "there should be no hesitation in condemning hate speech or white supremacy by name."
Whatever their motivations for exiting, any CEO joining the advisory council should have known what to expect because there was little mystery about Trump's policy positions, said Nick Donatiello, a lecturer on governance topics at the Stanford Graduate School of Business. "You can say 'Gee, couldn't some of this have been anticipated?' "
The CEOs remaining on the advisory group -- including those from Dow Chemical, General Electric and Wal-Mart Stores -- all have their own "risk calculations" to make, said John Rice, CEO of Management Leadership for Tomorrow, a nonprofit that helps companies, including Goldman Sachs Group and Alphabet Inc.'s Google, find minority talent. And "they know they will get called out."
Trump's Twitter fury seems to hold less powder these days. While his previous criticisms of companies or their executives have exacted retribution in the stock market, Merck's stock never faltered Monday -- closing about half a percentage point higher for a second straight day of gains.
Still, most corporate leaders continue walking the narrow line, working with the Trump administration to help shape policies while aiming not to alienate customers and shareholders who oppose Trump.
"Having a place at the table when big issues are being discussed" is of great important to executives and also to the president, Post said. "There is nothing more credible than the CEO's voice in issues that matter."
Business leaders, including JPMorgan Chase & Co.'s Jamie Dimon and Apple's Tim Cook, denounced racial intolerance, condemned hate speech or expressed shock over Saturday's events in Charlottesville, where a rally participant rammed a group of counter-demonstrators with his car, killing one and injuring at least 19 others.
But publicly issued applause for Frazier from his colleagues was scant. One, Hewlett Packard Enterprise's Meg Whitman, said in a tweet, "I'm thankful we have business leaders such as Ken to remind America of its better angels." Unilever's Paul Polman praised Frazier for standing up "for the moral values that made this country what it is."
It was glaring that there weren't similar comments from those CEOs advising the president as members of various councils, said Jeffrey Sonnenfeld, senior associate dean for leadership studies at the Yale School of Management.
"They are all afraid, individually, to stand out," he said. "It's absolutely fine to have a seat at the table -- but you have to open up your mouth."
The CEOs who resigned from the White House groups earlier did so over policy disagreements, with Musk and Iger leaving in June to protest Trump's decision to withdraw the US from the Paris international agreement on climate and Kalanick departing because of the president's stance on immigration. Kalanick resigned as CEO in June.
Most companies with CEOs on the manufacturing panel didn't respond to requests for comment or declined to comment. Those that did reinforced their support for diversity and opposition to bigotry while stressing the value of being engaged with the president on business matters.
Campbell Soup said CEO Denise Morrison would remain a member because "we believe it continues to be important for Campbell to have a voice and provide input on matters that will affect our industry, our company and our employees in support of growth."
AFL-CIO President Richard Trumka said the union is "assessing our role" on the manufacturing panel, which he said in a statement "has yet to hold a real meeting." At this point, he said, "There are real questions into the effectiveness of this council to deliver real policy that lifts working families."
Who's next? That's the big debate, said Davia Temin, head of the New York-based crisis-management firm Temin & Co.
"This conversation is viral in boardrooms right now."
