Despite lofty rhetoric from politicians who vowed in the aftermath of the 2008 financial crisis to hold Wall Street accountable, U.S. Justice Department statistics show a "long-term collapse" of federal white collar crime prosecutions, which are down to their lowest level in 20 years, according to a new report from Syracuse University.

The analysis of thousands of records by the university's Transactional Records Access Clearinghouse (TRAC) shows a more than 36 percent decline in such prosecutions since the middle of the Clinton administration, when the decline first began. While there was an uptick early in Barack Obama's presidency, current projections indicate that by the end of the 2015 fiscal year, such prosecutions will be at their lowest level since 1995.

But that doesn't mean white collar crime itself—which involves a wide range of activities such as health care fraud and the violation of tax, securities, antitrust, federal procurement, and other laws—is on the wane.

"The decline in federal white collar crime prosecutions does not necessarily indicate there has been a decline in white collar crime," the researchers are swift to point out. "Rather, it may reflect shifting enforcement policies by each of the administrations and the various agencies, the changing availabilities of essential staff and congressionally mandated alterations in the laws."

They add that "because such enforcement by state and local agencies for these crimes sometimes is erratic or nonexistent, the declining role of the federal government could be of great significance."

Furthermore, failure to prosecute white collar crimes does more than let individual fraudsters off the hook, as journalist Glenn Greenwald argued in 2013:

The harms from this refusal to hold Wall Street accountable are the same generated by the general legal immunity the US political culture has vested in its elites. Just as was true for the protection of torturers and illegal eavesdroppers, it ensures that there are no incentives to avoid similar crimes in the future. It is an injustice in its own right to allow those with power and wealth to commit destructive crimes with impunity. It subverts democracy and warps the justice system when a person's treatment under the law is determined not by their acts but by their power, position, and prestige. And it exposes just how shameful is the American penal state by contrasting the immunity given to the nation's most powerful with the merciless and brutal punishment meted out to its most marginalized.

But while news of the 20-year low is troubling, it's not particularly surprising. As journalist David Sirota noted on Thursday for the International Business Times:

In 2012, President Obama pledged to "hold Wall Street accountable" for financial misdeeds related to the financial crisis. But as financial industry donations flooded into Obama’s reelection campaign, his Justice Department officials promoted policies that critics say embodied a "too big to jail" doctrine for financial crime.

Sirota went on to point out, both the former head of the Justice Department's criminal division, Lanny Breuer, and former Attorney General Eric Holder made similar remarks at the time. "Prior to serving in the Obama Justice Department, both Breuer and Holder worked at white-collar defense firm Covington & Burling," Sirota wrote. "Both of them went back to work for the firm again immediately after leaving their government posts."