If you want to see the hashtag #TooFarLeft go viral, just get a former world leader—preferably one who is a Democrat—to denounce Left Twitter.

After it was reported Friday that former U.S. President Barack Obama told a room full of "wealthy liberal" Democratic Party donors that voters ultimately won't go for candidates offering political visions he suggested were too ambitious and radical, progressives online reacted critically to Obama advising the party to sideline "certain left-leaning twitter feeds" and what he termed the "the activist wing of our party."

According to the New York Times, which first reported on Obama's "too far left" advice:

While Mr. Obama did not single out any specific primary candidate or policy proposal, he cautioned that the universe of voters that could support a Democratic candidate—Democrats, independents and moderate Republicans—are not driven by the same views reflected on "certain left-leaning Twitter feeds" or "the activist wing of our party."

"Even as we push the envelope and we are bold in our vision we also have to be rooted in reality," Mr. Obama said. "The average American doesn't think we have to completely tear down the system and remake it."

Specifically not mentioned by name but clearly a target of the comments was Sen. Bernie Sanders, who has made the phrase "political revolution" central to his 2020 primary campaign. Sen. Elizabeth Warren, also running for the nomination, was likely another candidate the former president had in mind as she, along with Sanders, has used her campaign to argue that the U.S. political and economic systems are rigged against working people in favor of the wealthy and corporations—a dynamic that is going to need massive "structural change," the U.S. senator from Massachusetts says, if it is to be undone.

Sometimes called "Left Twitter" as shorthand, the broad moniker is characterized as Democratic Party members more in the vein of Sanders or those who represent a progressive flank of the spectrum that identify as democratic socialists, progressive Democrats, or left-wing independents. Not an official club that has a membership, any influential—or possibly strident—voices on the progressive left who use social media to share viewpoints and engage with the latest political developments, appeared to be the target of Obama's warning.

In turn, many who fit the description were not going to let the former president—especially a Democrat who swept to power in 2008 on the campaign promise of "hope and change"—get away with the comments without a characteristic retort. On Saturday, the hashtag #TooFarLeft was trending on Twitter.

Political operative Peter Daou, who took credit for launching the hashtag, said: "I launched the #TooFarLeft tag because I've had it with Republicans, media elites, and corporate Dems enabling fascists while denigrating those who seek economic and social justice as 'too far left.'  I'd like to ONCE hear them complain America is too far right."

And so, a brief sample of reactions:

"Obama telling a room of wealthy donors to support candidates that protect their wealth, which comes at the expense of helping everyday people, is [heartbreaking]," tweeted Melanie D'Arrigo, a progressive activist currently running for U.S. Congress in New York's 3rd District against a more centrist incumbent. "This is exactly why everyday people want a political revolution. Government isn’t working for them."