Officers of any firm that manages money for Indiana's pension fund are not allowed to donate to Donald Trump's presidential campaign.

That's because the state's pension fund is controlled by Donald Trump's running mate, Gov. Mike Pence. Pay-for-play regulations established by the Securities and Exchange Commission prohibit firms handling pension fund money from using campaign donations to influence officials who oversee their contracts.

Feinberg, like many hedge fund managers, can legally sidestep the pay-to-play rule by donating not directly to the presidential campaign - but to a presidential Super PAC. Those groups are supposed to be independent from campaigns - although the coordination between PACs and campaigns has become particularly rampant and overt this election cycle.

The half-million-dollar donation was made to Rebuilding America Now, one of the major Super PACs airing campaign commercials in support of the Trump-Pence election effort.

According to the law firm Sidley Austin, which published a fact sheet on the pay-to-play rule, Pence appoints the trustees of the Indiana pension system, a power that triggers the SEC rule on campaign contributions. Pensions & Investment, an industry trade publication, has also pointed out that a number of Trump-supporting hedge fund managers, including Feinberg, face restrictions because they manage Indiana's pension money.

Indiana's retirement system initially invested $3 million into a Cerberus fund in 2003, followed by a $78 million investment into another Cerberus fund in 2006, according to an interview. The hedge fund became controversial following the Sandy Hook Elementary School mass shooting in 2012 because Remington, the company that made the Bushmaster rifle used by shooter Adam Lanza, is owned by Cerberus Capital. Cerberus Capital is still listed in the most recent annual report for the Indiana retirement system.

The rules were originally promulgated in 2010 to deter rampant corruption in pension contracts. Hedge funds and other managers of pension money have been accused of aggressively courting pension contracts, which can earn the funds tens of millions of dollars a year in management fees.

Several governors with broad authority over pension contracts, however, have managed to sidestep the SEC rules by simply using third party campaign entities. Gov. Chris Christie, R-N.J., notably won reelection using the Republican Governors Association, heavily funded by firms that won lucrative pension fund contracts.