Democratic candidate Hillary Clinton during the final presidential debate in Las Vegas on Wednesday. (European Pressphoto Agency/Andrew Gombert)

Hedge fund manager S. Donald Sussman has given a total of $21 million to the top super PAC supporting Hillary Clinton, putting him on track to be the Democratic nominee's biggest political backer this cycle.

In an interview with The Washington Post, Sussman said he gave Priorities USA $6 million in September and another $2 million this month, bringing his total to $21 million.

The Florida-based investor said he has contributed $40 million to Democratic super PACs and allied groups in 2016, double what he had planned to spend at the beginning of the election. He said he was driven by the desire “to leave my children a better country” by helping elect candidates who will restructure a system that allows such huge donations in the wake of the Supreme Court's Citizens United decision.

“It’s very odd to be giving millions when your objective is to actually get the money out of politics,” he said. “I am a very strong supporter of publicly financed campaigns, and I think the only way to accomplish that is to get someone like Secretary Clinton, who is committed to cleaning up the unfortunate disaster created by the activist court in Citizens United.”

The founder of the Paloma Fund, who has helped raise money for the Clintons since the 1990s, insisted he is not looking to get any personal benefits from his contributions.

“I won’t make any more money with clean elections,” Sussman said. “A lot of people are major donors because they want to become something. I am who I want to be.”

S. Donald Sussman

Sussman said he has had limited interaction with Clinton as she has made her second presidential run — just a quick conversation in which they discussed overhauling the campaign finance system. “I’m not into the face time with the politicians,” he said. “I have had a four-minute conversation with her, where she assured me this is a top priority.”

Sussman's $6 million contributions in September helped Priorities USA raise record sums for the second month in a row. The super PAC collected $24.6 million, boosting its total fundraising for the cycle to $156 million.

Other top donors for the month included hedge fund founder Steve Mandel ($2.5 million), Facebook co-founder Dustin Moskovitz ($2.5 million) and Chicago venture capitalist J.B. Pritzker and his wife M.K. ($2.5 million), according to a Federal Election Commission filing released Thursday night.

Priorities USA had $22 million in the bank heading into October.

Anu Narayanswamy contributed to this report.