KEY POINTS Obama has hardly criticized Trump over the past three years for what he calls a "wise American tradition"

On Tuesday, however, Obama took a swipe at Trump, tweeting Americans should "demand better of our government"

As of Wednesday morning, there are 188,578 confirmed cases of COVID-19 in the U.S. and 3,890 deaths

Like most of his predecessors, former president Barack Obama has gone quietly into the post-presidential night, and has refrained from public commentary about the actions of his successor.

Over the past three years, the 44th president has avoided directly criticizing president Donald Trump in what Obama says is the "wise American tradition of ex-presidents gracefully exiting the political stage."

He strayed from that promise in September 2018 when he called on young voters to "restore some semblance of sanity to our politics" ahead of the midterm elections that gave Democrats control of the House and more oversight over Trump.

During the raging COVID-19 crisis, Obama has been more active on social media, but has chosen to praise Americans such as doctors and health workers leading the fight against the growing pandemic. He's shared advice from public health experts, and has kept to the "wise American tradition" he talked about.

But Trump's erratic handling of the federal response to the coronavirus crisis, and his early denial of its severity, seems to have forced Obama to reconsider his keep quiet mantra.

In a rare exception to this practice, Obama took to Twitter Tuesday to deliver a veiled criticism of Trump's non-response to the COVID-19 pandemic that threatens to take the lives of more than 200,000 Americans before it spends itself. He tweeted to his 11.4 million followers:

"We've seen all too terribly the consequences of those who denied warnings of a pandemic."

He then tweeted a link to a Los Angeles Times article addressing the rollback. "We can't afford any more consequences of climate denial. All of us, especially young people, have to demand better of our government at every level and vote this fall."

The second part of Obama's tweet referred to Trump's move to eliminate strict Obama-era rules on air pollution. The tweet was possiblty Obama's way of calling on young people to remove Trump from office in November due to Trump's bungling the federal response to the pandemic and his anti-environment policies.

Trump has been criticized for his handling of the coronavirus outbreak. As of April 1, 3:23 GMT, there are 188,578 confirmed cases of COVID-19 in the U.S., with a death toll of 3,890, Worldometer reports. This death toll has eclipsed the number of Americans killed in the 9/11 attack.

Photo: Justin Sullivan/Getty Images

Some media outlets observe Obama becoming more engaged on social media due to the COVID-19 crisis, posting more frequently on Twitter and cross-posting to his Facebook account about postive and helpful information.

On Monday, Obama tweeted about a New York Times story he sees as “a useful summary of the current best thinking among public health experts on how we need to approach the fight against COVID-19 in the coming weeks.”

"Here’s a useful summary of the current best thinking among public health experts on how we need to approach the fight against COVID-19 in the coming weeks."

Last week, Obama posted links to stories about “big-hearted people” that have devised news ways to come together, “even while remaining apart.”

"Some great stories of big-hearted people coming up with new ways to come together -- even while remaining apart -- to help the vulnerable who face some very tough times ahead."