When Bernie Sanders brought up Hillary Clinton’s prodigious fundraising from Wall Street at the Nov. 14 Democratic presidential debate, Clinton called it an attack on her “integrity.” And in an interview this week, she said that “anybody who thinks they can influence me on that ground doesn’t know me very well.”

But the fact remains that the Clinton campaign is fundraising heavily from Wall Street. Contributions from the securities and investment industries comprise her fourth-largest pile of campaign money, totaling $2,044,471. Commercial banks have given $443,519 directly to her campaign.

One major donor to her Super PAC, Priorities USA, is Donald Mullen Jr., a man who was singularly able to profit from the financial crisis both before and after the crash of the housing bubble.

Mullen, while a Goldman Sachs employee, pioneered the trades that allowed the mega-bank to profit from the collapse of the housing market. Mullen’s team utilized financial instruments called collateralized debt obligations to essentially bet against subprime mortgages.

A 2010 Senate investigation brought to light emails between Mullen and his Goldman colleagues. As his colleagues began to see the decline of the market, Mullen wrote cheerfully, “Sounds like we will make some serious money.”

In 2012, Mullen left Goldman Sachs to do the opposite of what he did in 2007: He started a hedge fund, the purpose of which was to buy up foreclosed homes and rent them out. New York magazine’s Kevin Roose described the career change this way: “A guy whose most famous trade was a successful bet on the full-scale implosion of the housing market is now swooping in to pick up the pieces on the other end.”

Mullen gave $100,000 to Priorities USA Action on June 30. According to Federal Election Commission data, this is the largest single contribution he has made to any soft money organization in his giving history. (In total, he has given $220,000 to soft money groups and $529,621 in individual contributions.)

Interestingly, in 2008 he gave $30,800 to the Obama Victory Fund, $2,300 to the Obama campaign, and $28,500 to the Democratic National Committee. But in 2011, he gave $2,500 to the Romney campaign and nothing to Obama, reflecting how much of the finance world abandoned Obama in 2012 to tilt toward Romney. Now it appears that the Clinton campaign has won him back.

Mullen could not be reached for comment.

Back in the last presidential election, Priorities USA used both the foreclosure crisis and Wall Street as campaign issues against the Republicans. In a 90-second ad hitting Mitt Romney, for instance, the Super PAC used a clip of the former Massachusetts governor saying that we shouldn’t “try and stop the foreclosure process. Let it run its course and hit the bottom.”

Today, Priorities USA is running ads focusing on a variety of issues, but avoiding direct attacks on Wall Street. Its primary social media account, on Twitter, has mentioned Wall Street only once, pointing to an article about Clinton’s financial plan that, as it turns out, leaves big banks intact.

During the back-and-forth with Sanders, Clinton cited her support for rebuilding lower Manhattan as a reason the finance industry came to her aid. But six months prior to 9/11, then-Senator Clinton voted for the industry’s top legislative priority at the time — a bankruptcy law rollback. That was a complete reversal from her position as first lady, when she told then-professor Elizabeth Warren in a private meeting, “Professor Warren, we’ve got to stop that awful bill.”

The industry started to pour money into the Clintons’ personal bank accounts before 9/11. Speeches from Bill Clinton brought in $250,000 from banks in the lead-up to the bankruptcy vote. Simultaneously, as David Sirota and Andrew Perez have reported, the candidate Hillary Clinton received $1.1 million from the securities and investment industry during her 2000 Senate race.

Top photo: Hillary Clinton in New York in July.