Elizabeth Warren is branching out.

The Massachusetts senator, who has made a career of unfairly maligning bankers and other alleged capitalist malefactors, is now smearing the criminal justice system, too.

In a speech at a historically black college in New Orleans, she declared that “the hard truth about our criminal justice system: It’s racist … I mean front to back.”

Her riff is a sign that the Democrats are going to leaven their lurch toward socialism with a condemnation of America as fundamentally racist. After helping fuel Donald Trump’s rise in 2016 with loose rhetoric about the bigotry of cops, Democrats hope to dislodge him in 2020 with even more sweeping accusations of systematic racism.

The U.S. criminal justice system is obviously a legitimate topic of debate. The war on drugs has been a blunderbuss mistake, and we should be reconsidering how many people we jail, and how we do it and why. But the contention that U.S. law enforcement is a product of racial hatred is a paranoid lie, from top to bottom, from beginning to end, from front to back.

The basis of the racism charge is the obvious disparities in the numbers. Blacks are 13 percent of the population, yet they account for 38 percent of state prisoners, and for more than roughly 30 percent of fatal police shootings.

The driver for mass incarceration, we are always told, is a racist war on drugs. But this is a myth. In his book “Locked In,” John Pfaff notes that at its height in 1990, the share of state prisoners serving time for drugs was just 22 percent. The proportion fell to less than 16 percent in 2014. So you could release all drug offenders and still leave mass incarceration intact. And you wouldn’t just be releasing black prisoners — 33 percent of white inmates in state prisons are drug offenders, a slightly smaller percentage than the 38 percent of black inmates who are drug offenders.

It is true that the incarceration rates for drug offenses are much higher for blacks. This may be a product of enforcement bias, or other factors such as whites are more prone to use private, as opposed to open-air, drug markets. “Little rigorous empirical work has been done to test these theories,” Pfaff writes. “It’s not uncommon to see someone simply assert that the proportions of whites and blacks who use and sell drugs are the same, but with very little data to support the claim.”

The biggest reason for the overall disparity in incarceration is different rates of offending. Blacks account for about 50 percent of homicides. It’s not that the police are simply making up these crimes. The numbers for violent crime accord with reports from crime victims of the race of their assailants.

The same applies to police shootings. Joseph Cesario, a professor of psychology at Michigan State University, writes that “the differences in involvement in criminal situations between black and white citizens fully explains the population-level disparity in fatal police shootings.”

Now, it’s entirely fair to argue that different rates of offending are a function of the vestiges of racism, and that it is urgent to pursue criminal justice reform given how the status quo affects black families and communities. But the idea that we are living in a latter-day apartheid South Africa, with a system designed to jail and immiserate blacks out of sheer maliciousness, is contemptible, poisonous and wrong.

It is telling that Elizabeth Warren is going there. There are two reasons. One is that she has a Bernie Sanders problem: She is (to all appearances) a white politician who has overwhelmingly devoted herself to economic issues. She needs to play identity politics catch-up. Two, in reaction to Trump, the left is embracing a sweeping indictment of America as undemocratic and racist at the core.

Warren’s performance shows that the party is prepared to consider no critique of America too radical or out of bounds.

Rich Lowry is a syndicaed columnist. He can be reached via email at: comments.lowry@nationalreview.com.