One of America's most iconoclastic judges, Jed Rakoff, recently attacked rampant plea bargaining that leads many innocent people to plead guilty.

We recently spoke to Rakoff about why America's prosecutors don't want to to get rid of the mandatory minimum sentences that perpetuate this plea bargaining.

Mandatory minimum sentences were enacted during the crime wave of the 1970s and 1980s and force judges to mete out certain prison sentences without regard for mitigating factors. Prosecutors can charge defendants with crimes that carry stiff mandatory minimum sentences, making these (often poor) defendants reluctant to take their chances at trial.

In his recent essay in The New York Review of Books, Rakoff says mandatory minimums have allowed prosecutors to "bludgeon defendants into effectively coerced plea bargains."

Rakoff — who's famous for blocking the SEC's attempt to settle a case with Citibank — argued in his recent New York Review Of Books essay that prosecutors abuse their power. Specifically, he argues, they're exploiting their ability to scare defendants into pleading guilty in exchange for a reduced sentence.

This is a system that leads 97% of federal criminal defendants to plead guilty if their cases aren't dismissed, and it is one that rarely exposes all of the facts of a case to either the judge or the jury.

If mandatory minimums were eliminated, there would likely be fewer plea bargains. But that's probably not going to happen any time soon, Rakoff told me recently over the phone.

"When Attorney General Holder suggested even some modest reforms in sentencing, a great many prosecutors including many in his own department came down on him and were very critical," Rakoff said.

"They think they need this weapon [mandatory minimums] to coerce cooperation, so they’re looking at it from a different standpoint," he added. "So many of the big cases are made through flipping cooperators, and they think this gives them the weapon they need to flip a cooperator."

For his part, Rakoff doesn't believe threats of insanely long prison sentences are necessary to flip cooperators. The threat of jail alone is usually enough.

"Jail is a really nasty place, and nobody really wants to go there," Rakoff said. "I don't think mandatory minimums are necessary at all for getting cooperators, but the present prosecutors think they are."