Just before she unveiled a sweeping plan to transform America's criminal justice system, Sen. Elizabeth Warren on Tuesday highlighted a prime example of how that system caters to the interests of the rich and powerful.

In a letter to the Justice Department, Warren, a Massachusetts senator and 2020 Democratic presidential candidate, demanded to know why President Donald Trump's political appointees last year weakened financial penalties against big banks that engaged in fraudulent behavior in the run-up to the 2008 Wall Street crash.

"It's not equal justice when a kid with an ounce of pot can get thrown in jail, while a bank executive who launders money for a drug cartel can get a bonus."

—Sen. Elizabeth Warren

"These weak settlements send a clear message to financial institutions and white-collar criminals that they can evade accountability as long as they are wealthy and well-connected," Warren wrote. "It is unconscionable that the administration is refusing to hold corporate criminals fully accountable for their role in the financial crisis."

"The American public," Warren added, "has a right to know how and why prosecutors who worked to hold banks responsible for the financial crisis were forced to agree to meager settlements that amount to pocket change for the banks."

But the U.S. criminal justice system works rather differently for those without deep pockets, high-powered lawyers, or influence in government, a point Warren emphasized in a Medium post Tuesday as she detailed her plan to tackle America's crisis of mass incarceration.

"Four words are etched above the Supreme Court: Equal Justice Under Law. That's supposed to be the promise of our justice system," the Massachusetts Democrat wrote. "But today in America, there's one system for the rich and powerful, and another one for everybody else."

"It's not equal justice when a kid with an ounce of pot can get thrown in jail, while a bank executive who launders money for a drug cartel can get a bonus," Warren said. "It's long past time for us to reform our system."

Warren's plan calls for repealing the bulk of the 1994 crime bill and confronting the disastrous consequences of America's war on drugs, both of which the Massachusetts Democrat characterizes as political "choices that together stack[ed] the deck against the poor and the disadvantaged."

The senator's platform also proposes ending cash bail, demilitarizing local law enforcement, banning for-profit prisons, and expanding mental health treatment programs.

"By spending our budgets not on imprisonment but on community services that lift people up," said Warren, "we'll decarcerate and make our communities safer."

In addition to changing how the criminal justice system works for the poor and disadvantaged, Warren's plan would also take on the system's favorable treatment of the wealthy.

"Equal justice," Warren said, "also means an end to the impunity enjoyed by those with money and power."

The senator continued:

Instead of criminalizing poverty and expanding mass incarceration, I've proposed a new criminal negligence standard for executives of corporations with more than $1 billion in annual revenue when their company is found guilty of a crime or their negligence causes severe harm to American families. Instead of locking up people for nonviolent marijuana crimes, I've proposed putting pharmaceutical executives on the hook to report suspicious orders for controlled substances that damage the lives of millions. And I've proposed new certification requirements for executives at giant financial institutions so that we can hold them criminally accountable if the banks they oversee commit fraud.

Warren's plan comes days after her 2020 Democratic presidential rival Sen. Bernie Sanders (I-Vt.) released his criminal justice platform, which also calls for ending cash bail, banning private prisons, and other steps toward comprehensive reform.

In a series of tweets on Tuesday, Warren said the U.S. "can create real law and order and real justice in our country by making long overdue big, structural change."

"The U.S. makes up 5 percent of the world's population, but nearly 20 percent of the world's prison population," Warren said. "Instead of putting people in prison, we should focus on services that lift people up."