In the heated debate over California’s statewide marijuana legalization initiative, there are plenty of arguments for passing the initiative. But as the still long-shot effort chugs toward Election Day next week, its supporters are trying to break through with a core piece of their case: That pot prohibition has driven extraordinary racial disparities in both policing and incarceration.

Proposition 19 would legalize some marijuana-related activities. If passed, people over 21 would be allowed to possess up to an ounce of marijuana. Adults would be allowed to use it in their homes or in licensed public facilities, and would be allowed to grow marijuana at home in a space no larger than 25 square feet.

For the state’s struggling economy, Prop 19 would also allow cities to decide whether and how they want to tax the sale of pot. The sale and consumption of medical marijuana is already legal in California.

In an effort to jump start the flagging campaign, billionaire financier George Soros this week donated $1 million to a committee the Drug Policy Alliance established to support Prop 19; Soros is on the Alliance’s board. As he made the donation, he wrote in Tuesday’s Wall Street Journal that he supports the initiative both because it makes financial sense and because pot prohibition has been racist in its inception and its implementation:

The racial inequities that are part and parcel of marijuana enforcement policies cannot be ignored. African-Americans are no more likely than other Americans to use marijuana but they are three, five or even 10 times more likely—depending on the city—to be arrested for possessing marijuana. I agree with Alice Huffman, president of the California NAACP, when she says that being caught up in the criminal justice system does more harm to young people than marijuana itself. Giving millions of young Americans a permanent drug arrest record that may follow them for life serves no one’s interests. Racial prejudice also helps explain the origins of marijuana prohibition. When California and other U.S. states first decided (between 1915 and 1933) to criminalize marijuana, the principal motivations were not grounded in science or public health but rather in prejudice and discrimination against immigrants from Mexico who reputedly smoked the “killer weed.”

Even cops admit that strict drug laws unfairly impact blacks and Latinos. “The white kids are not swept up in this because they are able to have the resources to get out of it if they are caught,” former LAPD sergeant and a member of Law Enforcement Against Prohibition William Cox told NPR. “If they are white, middle-class and acting respectfully toward the officers, they’re told to go home.”

The numbers back up both Cox and Soros, and this week the California NAACP released a new report that gathers the now-familiar data. In every single one of California’s top 25 largest counties, blacks are arrested for pot possession at two, three and sometimes even four times the rates of white people. Blacks in Los Angeles County are arrested for pot possession at 332 percent the rates of white people.

But when the California chapter of the NAACP came out in support of Prop 19 this summer, it set off a controversial debate in the black community.

“This is not a war on the drug lords, this is a war against young men and women of color,” Huffman said at the time. “Once a young person is arrested and brought under the justice system, he or she is more likely to get caught in the criminal justice system again, further wasting tax dollars.”

On the other side, Bishop Ron Allen has emerged as the black community’s major opponent to Prop 19. “I don’t believe that the blacks are targeted. I need to say that upfront,” Allen told NPR. Allen argues that legalizing the drug will encourage people to abuse it, and that what poor neighborhoods need is a traditional program that focuses on job creation and education.

Except that police will likely continue to crack down on blacks and Latinos at disproportionate rates while poor communities wait on those social programs.

The state recently passed a law reducing possession of an ounce of pot from a criminal misdemeanor to a civil infraction. Prop 19 supports, including the NAACP, argue that this change in law won’t likely change the policing practices that give rise to such disparate impacts on black and Latino communities. The California NAACP warns in its recent report that under the new law, it will be impossible to track how many civil infractions police give out. Misdemeanor arrest data is publicly available, but the state does not track or distribute infraction data. “In effect, the policing of marijuana possession will become even more hidden and invisible,” the report says.

With around $14 billion in annual sales, marijuana is already California’s number one cash crop, as it is for the entire United States. Currently it’s an untaxed entity; economists have recently come out in support of pot legalization for the simple economic argument. According to California tax collectors, Prop 19 would bring in about $1.3 billion a year in taxes alone, revenue that the bankrupt state could desperately use.

Critics warn though that the state will not be able to collect taxes on what remains a federally banned substance, and Attorney General Eric Holder has indicated he will stop Prop 19 from going into effect if it passes.

Then there’s the practical, common sense talking points about marijuana itself: “No one in the history of marijuana use has ever died of an overdose from marijuana,” Stephen Downing, a retired deputy chief of the LAPD, told NPR.

Nonetheless, the bill is not polling well—Los Angeles Times/USC numbers published this week showed that voters opposed it 51 percent to 39 percent. The New York Times reports that just 40 percent of black voters support Prop 19, and 52 percent oppose the bill. Whites, on the other hand, support Prop 19 by a decent margin: 48-43.

Blacks make up less than 10 percent of California’s population, but make up 18 percent of those arrested in the state and 32 percent of the state’s prison population.

This article was originally published on ColorLines.