This month, John Lester Gross III, a 48-year-old Californian, became another casualty in the federal government’s escalating war on marijuana. He plead gulity and was sentenced to 19-plus years for creating and running a dispensary in Sacramento and a nearby farm, where federal agents said they found 2,800 plants and 100 pounds of trimmed pot.

Like pot entrepreneurs in other states with non-federal laws allowing medical marijuana, Gross thought he was operating under state law, and most critically, after the federal Department of Justice told its prosecutors to back off marijuana cases early in President Obama’s first term. But California’s four U.S. attorneys decided that they did not like the industry’s rapid growth and began enforcing a gamut of federal laws to destroy it, especially taking aim at the large cultivators and retailers.

Prosecutors appointed by Obama, such as Andre Birotte, Jr., the first African-American to hold the post in the district where Los Angeles is located and a lawyer praised by the civil rights leaders, recently told a local public radio station that they were acting with prosecutorial discretion by not going after caregivers and patients, but targeting “drug dealers with storefronts.” U.S. Attorney Melinda Haag similarly touted her “measured approach” in seeking to seize the property of Berkeley’s biggest dispensary.

Longtime criminal defense lawyers don’t buy these "reasoned" explanations, however, because they know, as few Americans do, how powerful federal prosecutors are.

“You can’t trust the police to draw the lines of big-versus-small cases. You can’t trim the marijuana laws around the edges,” said Harvey Silverglate, a criminal defense lawyer and author whose books criticize a wide array of federal prosecutions. “Society has to make a decision. Is it willing to endure the expense and corruption that these laws engender?”

America’s political system is not about to stop the prosecutorial juggernaut filling federal prisons. It’s not just marijuana cases. The U.S. House is not about to pass immigration reform with amnesty and a path to citizenship, which accounts for a third of federal cases in 2012. Nor is it about to legalize marijuana, which accounts for a fourth of all federal drug offenses. Nor is it about to change how prosecutors with battlefield mentalities are held to account within the Justice Department.

“It is hard to overstate the power of federal prosecutors,” wrote New York University Law School professor Rachel Barkow, citing the massive growth in the number of federal crimes, the severity of punishments, the size of the federal prison population, and the prosecutors’ total control of the charges and punishment in almost every case.

“There are currently no effective legal checks in place to police the manner in which prosecutors exercise their discretion to bring charges, to negotiate pleas, or to set their office policies,” she wrote in 2008, when 95 percent of federal cases were not even tried before judges or juries, but instead filed with the federal courts as done deals.

Today, the number of federal cases tried is even smaller. Of the 84,173 cases resolved in 2012, federal statistics report that only 3 percent went to a judge or jury trial. Almost all, including the top categories—immigration, drugs, financial fraud, weapons offenses—had prosecutors who were, as Barkow wrote, “the final judges in their own cases.”

Even more disturbing is the percentage of cases where the accused did not harm others. The U.S. Sentencing Commission reported that in 2012 immigration and marijuana accounted for upward of 40 percent of recent prosecutions, even though offenders overwhelmingly were not commiting violent crimes. Eighty-four percent of the immigration cases involved being illegally in the U.S.

“The public is so often fed the impression that DAs and AUSA offices are operating as honest public servants whose integrity cannot be questioned. But of course they are the necessary partners in making the United States a prison nation, unparalleled in its mass incarceration of the population,” said Mara Verheyden-Hilliard, of the Partnership for Civil Justice Fund, which has sued police for abusing political protesters.

“I’m sure you know, in addition to the highlighted cases of gross prosecutorial misconduct, which are certainly more pervasive than is covered by the media, there is the day in and day out process by which defendants are falsely charged and overcharged and forced to plead guilty to some offenses in order to avoid the prosecutor’s threat of decades more of imprisonment,” she said. “It’s a terrible and vicious weapon, and coupled with the use of police lies accounts for the fact that 97 percent of cases don’t go to trial. It has effectively eliminated the constitutional right of defense for most.”

Let’s look at several ways that federal prosecutors operate without checks and balances. These prosecutors are nominated by the president and approved by the Senate for four-year terms. They run offices that can have dozens or hundreds of deputies working for them, where they both lead and take cases from all the federal police agencies.

1. Abuse of Prosecutorial Power

The everyday abuses of prosecutorial power Verheyden-Hilliard cites are hidden in the most recent Justice Department Office of Professional Responsibility reports that do not even cite names, courts, cases or changed verdicts when discussing a handful of professional misconduct complaints—such as falsifying or withholding evidence.

“Prosecutors think that they are doing the lord’s work and that they wear the white hat,” Jack Wolfe, a former federal prosecutor in Texas and now a defense lawyer told the Wall Street Journal, commenting on a USA Today series on prosecutorial abuses in late 2010. “When I was a prosecutor, I thought that everything I did was right… Even if you got out of line, you could tell yourself that you didn’t do it on purpose, or that it was for the greater good.”

Federal prosecutors are notoriously tight-lipped. However, there is one area of law where they have broken with their usual silence and described why they are interpreting the law at their discretion: the marijiana cases.

“The DOJ has made a centralized decision to avoid making centralized decisions,” said Columbia Law School’s Daniel Richman, who teaches federal criminal procedure and said the political decision by Attorney General Eric Holder to let local prosecutors do what they wanted was “outside the normal dynamic” where Washington keeps a tight rein on priorities.

“They are delegating to U.S. attorneys to do what they want to do,” Richman said, saying that the DOJ’s current pot policy “looks like the Prohibition Era,” referring to a century ago when alcohol was illegal but the public supported its use. In 2013, 17 states and the District of Columbia have legalized pot under different circumstances, most having to do with medical use, but U.S. attorneys have decided how tough to be in shutting down state-licensed operations.

Montana’s top federal prosecutor, Obama appointee Mike Cotter, arguably is the most aggressive, raiding greenhouses and dispensaries in full SWAT-team fashion without warning even as his state’s legislature was poised to revise its medical marijuana law. Cotter is seeking to put people away for life, saying marijuana has no medical value. As of this May, 31 defendants took plea deals, two went to trial and lost, and one charge—going after a provider’s accountant—was thrown out by a judge, the AP reported.

California’s four U.S. attorneys—Birotte, Benjamin Wagner, Melinda Haag, and Laura E. Duffy—have taken a slightly less draconian approach. Unlike Montana, they have warned targets, such as the landlord of Berkeley’s largest dispensary, to evict the dispensary or face property forfeiture proceedings—which are now underway. Birotte, arguably the most outspoken of the state’s federal prosecutors, said that the industry was growing too fast, making too much money and that wasn’t the same as helping the sick.

Drawing these legal lines are examples of prosecutorial discretion at play, Columbia Law School’s Richman said. “This is prosecutors being pushed to a legislative role. They are much more comfortable with taking direction from ‘main Justice’ [Washington].”

But the marijuana wars are escalating. In Colorado, which passed one of the country’s most liberal ballot initiatives last November, U.S. Attorney John Walsh has been going after dispensaries, and like in California, telling local pro-pot police officials that he’s turning his attention their way. “To be clear, this program is not at the direction of Washington, D.C.,” Walsh wrote to Boulder’s prosecutor, saying that he intended to shut dispensaries within 1,000 feet of public schools “at my direction as U.S. attorney.”

Like almost all federal prosecutions, most of the pot cases are not heard before judges or jury trials but instead are presented as guilty pleas where judges follow harsh federal sentencing guidelines. Drug law critics such as Families Against Mandatory Minimums note that "marijuana offenders are among the least likely of all drug offenders to receive a manadary minimum [sentence] for their offenses."

2. Overpunishment, especially among communities of color.

Overpunishment is not confined to drug cases. Immigration cases account for one-third of federal prosecutions. In 2012, 84 percent of these charges “involved illegally entering or remaining in the United States,” U.S. Sentencing Commission reported. “Another 9.8 percent involved alien smuggling.” More than 93 percent of defendants were men; 88 percent were Latino; and less than 82 percent entered high school.

In these cases, federal prosecutors are not in the driver’s seat like pot cases, but akin to bureaucrats pushing paperwork through the prison treadmill, Richman said. Syracuse University, which has a clearinghouse tracking all federal prosecutions, agreed, saying, “Virtually all federal criminal prosecutions for immigration offenses in April 2013 were referred by the Department of Homeland Security” by two of its agencies: Customs and Border Patrol and Immigration and Customs Enforcement.

Immigration policy and prosecutions are rife with injustice because of congressional "get-tough" attitudes and GOP-led opposition to paths to citizenship. One-fourth of the 8,000 or more immigration cases filed monthly by federal prosecutors are, predictably, along the Mexican border. Deputies working for U.S. attorneys Robert L. Pittman (West Texas), Kenneth Magidson (Southern Texas), Kenneth J. Gonzales (New Mexico) and Laura E. Duffy (Southern California) handle this caseload.

Recent Obama administration efforts to soften immigration enforcement, such as creating new rules for raids that prevent agents from entering homes without permission, do not appear to offset the volume of immigration prosecutions. Obama has consistently had double the rate of prosecutions compared to George W. Bush’s administration.

The immigration prosecutions highlight another fact of federal prison policy: that almost 70 percent of all federal inmates are not white. Two-thirds are also younger than age 40. Another frequently overlooked aspect of a large young and non-white prison population is what happens to these inmates when they leave jail and try to reintegrate in society.

“The most salient issues for progressives are the number of people in jail, reintegration into society and the use of police tactics that impose too many costs on a community,” said Columbia Law School’s Richman.

3. Going after low-hanging fruit, not the rich and powerful.

Progressives often wonder why federal prosecutors have not done more to go after white-collar crime, to offset the institutional racism of a system that imprisons far more people of color and poor people than whites. The global financial crisis created by Wall Street’s gambling in real estate and equity markets underscores this enduring question.

In late 2009, the Obama administration created the Financial Fraud Enforcement Task Force. Its website describes several hundred convictions for financial crimes such as “mortage scams that target the elderly, Ponzi schemes that shock the world, procurement fraud that steals money from our nation’s coffer, predatory lending that discriminates against vulnerable communities, securities fraud that undermines the trust and transparency of our markets.” In 2012, “fraud” accounted for 10.5 percent of prosecutions.

But some longtime criminal defense lawyers say they are not going after the most pivotal institutional players as aggressively as other categories of offenders.

“They didn’t go after much of anybody on Wall Street, where selling a stock that you know is valueless is a fraud—that’s a federal felony,” said Miles Gerety, a retired senior state public defender in Connecticut. “If you can prove that somebody called it ‘crap’ and is selling it, that’s a felony.”

Gerety said that he knows several federal prosecutors who were content to have Wall St. traders banned from the investment business for life instead of imprisoned.

Harvey Silverglate, the criminal defensew attorney and author whose books criticize federal prosecutorial excess, said many of the most egregious behaviors were legal—because financial industry lobbyists convinced Congress to gut consumer laws, just as the operators of privatized prisons are now lobbying Congress to increase federal minimum sentences. “It’s a political problem more than a legal problem,” he said.

The political arena also influences prosecutors in another important way—when not to bring cases, Columbia University’s Richman said, citing gun trafficking crimes. In 2012, firearms offenses accounted for 10 percent of federal prosecutions.

The National Rifle Association’s propaganda, in concert with right-wing demonizing of the Bureau of Alcohol, Tobacco, Firearms and Explosives—after it botched a weapons-tracing investigation in Mexico—has curtailed prosecution of gun trafficking crimes, he said. The result is that the majority of federal gun prosecutions involve charges of lone individuals acting violently with guns, but backing away from prosecuting firearms dealers or people trafficking the weapons.

4. Using the office as a stepping-stone to other offices.

Given the unbridled power of federal prosecutors, it’s not surprising that the post is seen as a stepping-stone to higher office. And indeed, some prosecutors politicize their office or use it as a publicity tool for other public posts.

That is the accusation from the attorney for Aaron Swartz, an open-democracy advocate and developer of Reddit who committed suicide in January at age 26 in the wake of Massachusetts Assistant U.S. Attorney Stephen Heymann pursuing jail time for his downloading of millions of scholarly articles from an academic database at M.I.T.

Elliot Peters, Swartz’ attorney, said Heymann’s insistance on six months jail time was part of pursuing “juicy-looking computer crime cases and Aaron’s case, sadly for Aaron, fit the bill.” In an extensive New Yorker profile, Peters said it was absurd that Heymann contended the academic articles were worth $2 million.

“I said, ‘What he took from JSTOR wasn’t worth anything! It was a bunch of, like, the 1942 edition of the Journal of Botany!’ The idea that Aaron should be sentenced the same way as someone who tries to beat someone out of two million dollars in a security-fraud scam? Someone who steals money from people?”

This kind of hard-bargaining, over-criminalization, and knowing the federal government holds almost all of cards is precisely what makes U.S. attorneys an imperial power center in what’s supposed to be a democratic system of checks and balances. As the Huffington Post reported, this was the second case where Heymann went after a computer hacker who ended up committing suicide.

But the majority of people who are put behind bars by federal prosecutors for non-violent crimes, especially drug and immigration offenses, are swallowed up by the system and don’t have high-profile defenders like Aaron Swartz.

It’s also arguable how much public pressure will change federal enforcement priorities. After USA Today published its series on prosecutorial misconduct in 2010, U.S. Attorney General Eric Holder dismissed the accusations and defended the Justice Department’s self-policing practices. Recent immigration reform proposals that could drastically undermine the prison treadmill appear to be dying in the GOP-controlled House.

Meanwhile, in California, some local officials are suing the U.S. attorneys over shutting down medical marijuana operations through property forfeiture actions. California’s top federal prosecutors complain that their decision to go after the industry has led to unfair criticism that obscures their other good work—like Birotte getting an $82 million fine against Walmart for water pollution under the federal Clean Water Act.

“It [marijuana] is far from the most important thing that we do,” Benjamin Wagner, the U.S. attorney for the Eastern District of California, told local reporters. “I did not seek the position of U.S. attorney in order to launch a campaign against medical marijuana.”

However, Wagner and the federal government’s three other top prosecutors in the state are not backing down on pot. And short of explicit congressional directives, there’s little that anyone can do to reel in the power of crusading federal prosecutors.