The hedge fund bought 53,100 shares of CCA stock worth about $1.89 million in the first quarter of 2004, records show. A year later, under Steyer’s management, Farallon boosted its acquisition to 5.5 percent of the outstanding stock of CCA, or 2.27 million shares valued at nearly $90 million.

The scope of Farallon’s investments in CCA prompted concern at Yale University more than a decade ago, when members of the university’s graduate teachers’ union publicly called on Yale to divest from Farallon, citing CCA’s management of issues of racial injustice, human rights abuses and disproportionate incarceration of racial minorities.

Steyer, in a March 17, 2004 letter to the students of Yale, defended his firm, saying “we are proud of the work we have done, and continue to do” for the portfolios of universities. He declined to meet with his critics at Yale.

While Steyer’s investments won attention at Yale a dozen years ago, they have never received widespread coverage in California.

But the resurrection of old controversies underscores the increased scrutiny that may be ahead for Steyer, who concedes that his career as a hedge fund manager may be political fodder.

“This is not the first time someone has attacked Farallon’s investments, and it won’t be the last,’’ he told POLITICO California in a statement on Saturday.

The Democratic activist, who is spending millions on national campaigns to boost voter registration as well as state ballot measures as he prepares ground for what many believe may be a 2018 gubernatorial run, said in his email statement: “I left my business and dedicated myself full-time to working for the public good because I want to spend the rest of my life making a positive impact in our state and our country.”

Regarding the hedge fund’s past investments in private prisons, he said: “We heard the concerns of student leaders — and in the end Farallon chose to sell the stock” in 2006.

The Correction Corporation of America website says it is “the fifth-largest corrections system in the nation, behind only the federal government and three states,’’ and says CCA houses nearly “70,000 inmates in more than 70 facilities, the majority of which are company-owned, with a total bed capacity of more than 80,000.” It operates five facilities in California, and houses thousands of California inmates in other states in partnership with the state department of corrections.

But criminal justice advocates say there have been long-running concerns about the operation of for-profit prisons, specifically with regard to racial justice issues.

Constance de la Vega, a professor of law at the University of San Francisco who wrote a 2014 study on the for-profit prison system for Human Rights Advocates, said those issues have included “the treatment that prisoners were receiving in these for-profit prisons,” in addition to disproportionate populations of racial minorities and immigrants.

She said of Steyer’s past investments: “I find it shocking, based on his (progressive) positions’’ on other issues, adding that many see “a basic problem with ... taking away people’s liberty and turning it over in private sector.”

Steyer told POLITICO California: “I strongly believe that our criminal justice system needs serious reform.”

He noted that he has strongly endorsed two ballot measures that aim to address those issues, Proposition 57, which calls for parole for non-violent criminals and juvenile court reforms, and Proposition 62, the death penalty repeal.

Political analyst Jessica Levinson, who teaches politics and ethics at Loyola Law School in Los Angeles, says that Steyer’s past careeer “will make fantastic fodder for his opponents — the slate mailers and radio ads are already written,’’ says Levinson. “People will say, ‘Why do you want someone who tries to make money off the worst kinds of companies?’”

But more recently, Levinson added, Steyer has “also engaged in an enormous amount of philanthropy. He can say, ‘That’s what I’m doing now,’” she said. “His opponents will raise it, and he will try and cleanse his record. And people may want to give him a second look.”

Indeed, a recent Sacramento Bee story revealed that Steyer, who has spent $10.8 million as of Monday in support of Proposition 56, a $2-per-pack tobacco tax, previously invested millions in big tobacco firms through Farallon’s hedge fund.

Steyer told POLITICO that he never supported those investments and that he even insisted on a vote among Farallon principals so his opposition would be on the record. He acknowledges the hedge fund’s myriad of past investments may open him up for criticism, now and in the future.

“I made a change in my life and my priorities to dedicate my time and my resources to fighting for issues that I believe can make life better for families in our state and our country,’' Steyer said in a statment this week. “I will continue to do so to the best of my ability for as long as I can.”