When Corinthian Colleges collapsed in 2015 under the weight of allegations the for-profit college misled students about job placement and graduation rates, it left thousands of students with debt and few palatable options.

Nearly four years later, some of its executives are facing the consequences of their alleged role in the school’s collapse, but a group of Democratic Senators led by Elizabeth Warren say they’re barely being held accountable.

Warren and her colleagues sent a letter to Jay Clayton, the chairman of the Securities and Exchange Commission, asking for “an explanation of the rationale” behind what they described as a “weak settlement” between the SEC and Jack Massimino, Corinthian’s former chief executive and Robert Owen, it’s former chief financial officer.

Massimino will pay $80,000 and Owen $20,000 to settle claims that the two failed to disclose risks to the company’s primary source of revenue — federal financial-aid funds — to the public and investors.

“This weak settlement by the SEC is an insult to the victims of Corinthian’s fraud,” the letter reads. “It neither holds executives truly accountable for their misdeeds nor deters future bad behavior. It represents a loss for taxpayers, investors, and the thousands of students that Corinthian defrauded.”

The SEC and lawyers for Massimino and Owen didn’t immediately respond to a request for comment on the Senators’ claims.

In the letter, Warren and her colleagues contrasted the executives’ fate with that of former Corinthian students, many of whom are still struggling under the weight of the debt they took on to attend the school.

After Corinthian collapsed, thousands of students were left with debt and either no degree or a degree worth very little in the labor market. As former Corinthian students clamored for relief, the Obama-era Department of Education under pressure from activists, created a formal process for borrowers who say they were misled by their schools. Those borrowers could use this process to apply to have their federal loans discharged under a law known as borrower defense to repayment.

But in the years since, the Betsy DeVos-led Department of Education worked to re-write these rules. Consumer advocates and states attorneys general have challenged these efforts in court. In the meantime, thousands of borrowers are waiting for relief. As of September 2018,139,000 claims for relief from borrowers — not all former Corinthian students — were awaiting a decision by the Department.

Corinthian was the first in a series of major for-profit colleges to collapse and, so far, the executives who ran the schools leading up to their demise have faced few major consequences. The former CEO and CFO of ITT Tech, which collapsed in 2016, agreed to pay $200,000 and $100,000 respectively to settle with the SEC over claims that the school misled investors about the impact of two failing student-loan programs on the company’s bottom line.

Just days before Warren and her colleagues sent her letter, another for-profit college chain was on the brink of collapse. Last week, the Department of Education cut off Argosy University cut from the federal financial-aid program. (Argosy includes dozens of schools across the country.) The agency also rejected a request by Argosy’s parent organization, Dream Center Educational Holdings, to convert Argosy into a nonprofit.

That decision came after Argosy failed to distribute stipends, the federal financial-aid money students rely on to pay non-tuition expenses, to its students, even though the Department says it sent that money to Argosy.

Historically, Warren has been one of the most aggressive critics of the for-profit college industry. Her campaign for president has yet to release her plans on college affordability and student debt, but this history suggests that tightening regulations on for-profit colleges would likely be part of that platform.

Senator Kamala Harris, a Democrat from California, another 2020 contender, told the audience at a CNN town hall earlier this year, “We need to get rid of the for-profit colleges that are preying on students.” The office of California Attorney General Harris won a judgement worth more than $1 billion against the school.