Radical left-wingers want to free half the nation’s prisoners—including many violent offenders—a move that would cause an upsurge in crime rates for decades to come. To many of today’s leftists criminality itself is an illegitimate concept. The mindless chanting of the slogan “no one is illegal” at open-borders rallies is part of the same school of thought. Spearheaded by the American Civil Liberties Union and bankrolled by radical speculator George Soros, the “end mass incarceration” movement wants to reduce the U.S. prison population by 50 percent within the next 10 to 15 years. This specific push is called the “Cut50”...