NEW YORK (AFP) - From television network ABC cancelling "Roseanne" and kissing goodbye to millions in lost ad revenue to Starbucks training staff against racial bias, corporate America is touting a moral backbone as the must-have asset of the Trump era.

"It's a profound change," said senior associate dean for leadership studies Jeffrey Sonnenfeld at Yale School of Management.

"It is emblematic of CEOs, generally of larger old-line enterprises that are jumping in to fill the void of a moral vacuum," he said.

It took Disney chief executive Bob Iger hours, if not minutes, to axe ABC's top-rated show on Tuesday (May 29) after household name and President Donald Trump's supporter Roseanne Barr fired off a racist tweet about a former president Barack Obama's White House adviser.

"Roseanne's Twitter statement is abhorrent, repugnant and inconsistent with our values," announced, ABC's Channing Dungey, the first black woman president of a major broadcast network.

Mr Iger's speed was unprecedented: universities waited years to rescind honorary degrees after Bill Cosby was accused of drugging and sexually assaulting women.

But it was not his first bold decision.

Last June, he and Tesla boss Elon Musk resigned from Mr Trump's advisory council in protest at the United States leaving the Paris climate deal.

Meanwhile in August, Merck CEO Kenneth Frazier led the way in quitting Mr Trump's manufacturing council after the president prevaricated in condemning white supremacists at a deadly rally in Virginia.

Starbucks this week decided to sacrifice millions in lost sales to close for an afternoon of nationwide racial-bias training, after two black men were arrested in a Philadelphia store in April.

On Thursday, vehicle retail website Autotrader.com pulled its sponsorship of Samantha Bee's "Full Frontal" television show after the comedian used a gendered four-letter expletive to refer to Mr Trump's daughter, Ivanka.

And following a Valentine's Day school shooting that killed 17 people, Walmart and Dick's Sporting Goods raised to 21 the minimum age for gun purchases, short-circuiting paralysis in US Congress on meaningful gun reform.

"The research indicates that morality in leadership is more important than it's ever been," said Dr James Lemoine, assistant professor of organisation and human resources at University at Buffalo School of Management.

"Paradoxically, the companies that focus less on profit and more on stakeholders make more profit in the long-term," he said.

He attributed the change to the rise of the millennial generation and social media, which has exposed individuals and companies to unprecedented transparency, as well as an American appetite to hold the powerful accountable.

"Cynics may say companies are just doing it so that they can get good press...but it also makes good business sense in the modern world because of how much more closely people are able to follow these companies," Dr Lemoine said.

It is a trajectory he traces back to former president Bill Clinton's impeachment, and popular discontent with former president George W. Bush following Hurricane Katrina and the Iraq War.

But Dr Sonnenfeld believed it is absolutely linked to Mr Trump and concerns that demagoguery is no longer on the fringes of society.

"The coarsening of public discourse is what they are responding to," he said. "That's why CEOs are moved to act because they can see how precious the balance of our national character is."

Perceived wisdom also considers the #MeToo movement, bringing to account powerful men accused of sexual misconduct, a result of Mr Trump's election despite accusations against him and himself bragging of being able to grab women.

Professor Nadine Strossen at New York Law School said that steps taken by society to combat racism and discrimination can be more effective than government censorship, even if she guards against a rush to judgement in some instances.

She welcomed the Starbucks training as a company taking responsibility to make society more positive. ABC, she said, sent "a very strong statement" about what was not tolerated in 21st century America.

"In fact, social pressure can exert an even more potent chilling effect than fear of punishment from the government," she said.

Dr Lemoine said business schools are now debating the traditional focus on profit-oriented forms of leadership, wondering if it was at least partly responsible for the early 21st century corporate scandals such as Enron.

"May be we need to teach more moral approaches to leadership, but then that opens up a whole other can of worms in that then we have to answer what are morals, what are ethics?" he asked.

"Do ethics require a business to take proactive steps to make the world a better place, in addition to its profit motivation?"