After establishment Democrats exploded over a column making the argument that former Vice President Joe Biden is too corrupt to credibly present voters an alternative to President Donald Trump in the 2020 general election, progressives presented more evidence from Biden's past that make the case against his candidacy.

A column Monday by Zephyr Teachout, a professor of law at Fordham University and supporter of the Democratic presidential bid of Sen. Bernie Sanders (I-Vt.), set off a firestorm for asserting Biden has a "corruption problem" and that his past makes the former vice president a "weak candidate" compared to others in the primary field.

"Here's the thing," wrote Teachout, "nominating a candidate like Biden will make it far more difficult to defeat Trump."

‘Middle Class’ Joe Biden has a corruption problem – it makes him a weak candidate | Zephyr Teachout https://t.co/Ooxb56VheB — Zephyr Teachout (@ZephyrTeachout) January 20, 2020

Teachout detailed three major areas of concern: Biden's prioritization of the financial industry over working Americans, his ties to the healthcare industry, and his connections to the fossil fuel industry. The potential for Trump to use Biden's record against him in a general election, said Teachout, should not be underestimated.

"Corrupt politicians always use whataboutism," Teachout wrote. "With Biden, we are basically handing Trump a whataboutism playbook."

Cenk Uygur, the Young Turks host running for Congress in California's 25th district, said on Twitter that the argument against Biden for corruption was an easy one to make.

"Of course Biden is corrupt," said Uygur. "He takes millions in campaign contributions and votes with his donors. It's obvious."

Establishment Democrats and members of the media cried foul over the piece, calling it an attack and placing the blame for it at Sanders' feet.

The Hill's Krystal Ball replied by noting the double standard in which it is off the table for Sanders and his team to mark legitimate distinctions between the senator and other candidates while his rivals are allowed to levy unfounded attacks against him.

"So the Sanders campaign isn't allowed to point things out that are objectively true, while other campaigns are celebrated for nasty invented smears," Ball tweeted of an attack on the campaign from New York Times columnist Paul Krugman. "Got it."

So the Sanders campaign isn’t allowed to point things out that are objectively true, while other campaigns are celebrated for nasty invented smears. Got it. https://t.co/e6Jjw8Rmk0 — Krystal Ball (@krystalball) January 20, 2020

Jon Schwarz, a writer for The Intercept, opined that Krugman's distaste for the attacks was based in his support for Biden and not in a real interest in keeping the primary fair.

"Note Krugman doesn't say anything here is false, and is not denying Biden is corrupt," said Schwarz. "Krugman surely knows Biden is corrupt (although in the standard Washington way, not the insane lurid Trump way). Krugman just objects to anyone mentioning these facts."

Sanders, for his part, disavowed Teachout's article and claimed not to believe Biden is corrupt in an interview with CBS News.

"Thanks for acknowledging this, Bernie," Biden tweeted in response. "These kinds of attacks have no place in this primary. Let's all keep our focus on making Donald Trump a one-term president."

Giving Biden the ability to pivot away from discussing that history and calling for ignoring it altogether, said Intercept journalist Mehdi Hasan, is a problem.

"It is political malpractice that none of his rivals have brought up Biden’s sponsorship of the infamous bankruptcy bill on behalf of the credit card industry in Delaware at a single TV debate so far," Hasan said, "which allows Biden to then put out tweets like this."

Journalist Sam Adler-Bell agreed and noted the possibility of the GOP taking advantage of a gaping hole in Biden's credibility with voters.

"Biden is corrupt and the Sanders campaign is justified in saying so," said Adler-Bell. "Just on electability grounds, Biden's record is a huge opening for Trump (also corrupt)."

As a number of progressives pointed out, Biden's history at the very least hints at corruption and nepotism of the kind described by Teachout and used by Republicans to defend Trump from impeachment over withholding aid to Ukraine until the country's leaders announced an investigation into Biden's son Hunter's employment by gas company Burisma.

"Our impeachment contains in its underlying facts that Biden's son made $600k/yr at a no-show Ukrainian gas company board job, so everyone needs to keep the lips zipped on Biden corruption for the moment." --> This is the amusing corner the Dems have walked themselves into. — Matt Bruenig (@MattBruenig) January 21, 2020 “Your son was working for the [credit card] company at the same time. In retrospect, wasn’t it inappropriate?”



—Tom Brokaw, 2008, quizzing Biden on the work he did for MBNA in the Senate while Hunter was on their payroll. https://t.co/a7KkQWV7Xf — Ryan Grim (@ryangrim) January 21, 2020 To be clear, @ZephyrTeachout is an expert on corruption and the substance of her article is correct.



People are outraged that she called Joe Biden corrupt, and yet no one has even attempted to refute what the article actually says. Because it’s verifiably correct. — cabral (@axcomrade) January 21, 2020

With the politics of impeachment looming and Biden's documented history of promoting the interests of corporate donors clear to anyone willing to look, the time to air out the current national frontrunner's record is now, said Current Affairs editor Nathan J. Robinson.

"If we don't point out the truth, we risk getting stuck with a corrupt candidate that Trump will crush," Robinson said.

Teachout, in her column Monday, called on Democrats to choose a different path.

"We still have time to break with this culture of corruption," wrote Teachout. "We don't have to choose Biden's way, which would give Trump a perfect foil."

"We have a rare opportunity to end a larger culture of corruption and we should take it," she added. "We will regret it if we don't."