A Mexican cartel chief, Jorge Roman, once called the drug war ‘a sham put on the American tax-payer’ that was ‘actually good for business’.
The only thing the drug cartels fear is legalization.

The introduction of medical marijuana laws has led to a sharp reduction in violent crime in US states that border Mexico, according to new research.
According to the study, Is Legal Pot Crippling Mexican Drug Trafficking Organizations? The Effect of Medical Marijuana Laws on US Crime, when a state on the Mexican border legalised medical use of the drug, violent crime fell by 13% on average. Most of the marijuana consumed in the US originates in Mexico, where seven major cartels control the illicit drug trade.
“These laws allow local farmers to grow marijuana that can then be sold to dispensaries where it is sold legally,” said the economist Evelina Gavrilova, one of the study’s authors. “These growers are in direct competition with Mexican drug cartels that are smuggling the marijuana into the US. As a result, the cartels get much less business.”
...They found that among the border states the effect of the change in law was largest in California, where there was a reduction of 15% in violent crime, and weakest in Arizona, where there was a fall of 7%. The crimes most strongly affected were robbery, which fell by 19%, and murder, which dropped by 10%. Homicides specifically related to the drug trade fell by an astonishing 41%.

Who coulda guessed? If there was only some historic example from the last century that could have allowed us to foresee this.
Of course, there is still some that will tell us contradictory bullsh*t like this.

Mexican Drug Cartels May Use Legal Marijuana to Increase Their Presence in Northern California

There are three problems with this article:

1. Buried in the article is this:

Calaveras authorities have never received a confession from arrested farmers that links them to Mexican drug cartels. Yet Frick and the California attorney general’s office believe the illegal weed goes into the nationwide pipeline coordinated by organizations such as the Sinaloa cartel and La Familia Michoacana.

So we have no evidence of this, but we'll try to scare you anyway.

2. It was official federal policy until last week.

The Justice Department marijuana enforcement policy that U.S. Attorney General Jeff Sessions rescinded last week was crafted to try and keep cartels and gangs out of the marijuana trade, the policy’s author told International Business Times.

3. Since when do the cartels deal in legal drugs?

4. All other measurable data from beyond our borders

Intellectuals at Mexican think tanks believe legalization in America has cut drug cartels’ earnings north of the border by as much as 30 percent—and that was when recreational cannabis was available in just a few states, not in eight states and for 65 million Americans and counting, as it is today.

Marijuana legalization has become overwhelmingly popular.

April 2017: CBS News

"Marijuana should be..."

Legal: 61%
Not legal: 33%

August 2017: Quinnipiac University

"Do you think that the use of marijuana should be made legal in the United States, or not?"

Yes: 61%
No: 33%

October 2017: Gallup

"Do you think the use of marijuana should be made legal, or not?"

Legal: 64%
Illegal: 34%

January 2018: Pew Research Center

"Do you think the use of marijuana should be made legal, or not?"

Legal: 61%
Illegal: 37%

This week Vermont became the 9th state to legalize recreational marijuana, and the first state in the country to legalize pot by an act of the Legislature rather than through a ballot measure.
Legalization could have enormous financial benefits.

The study, from cannabis industry analytics firm New Frontier Data, seeks to estimate the total economic impact of the nascent industry. Cannabis is legal in eight states, including California, which legalized recreational sales on January 1. Vermont is likely to join that list once Gov. Phil Scott signs a bill legalizing the possession of up to one ounce of marijuana into law.
The study assumes the tax revenue, which will add $131.8 billion cumulatively to the US Treasury by 2025, will come from a 15% retail tax, payroll tax deductions, and a 35% business tax. Sales tax alone on cannabis would add $51.7 billion to US coffers between 2017 and 2025.

I'm curious how much money can be saved by not wasting money on busting people for victimless crimes?
I only have bits of information about that.

A new report published in Health Affairs found that if all states had legalized medical marijuana in 2014, Medicaid could have saved $1 billion in spending on prescriptions.
The study by Ashley C. Bradford and W. David Bradford examined whether states with medical marijuana laws saw changes for prescription drugs among Medicare Part D enrollees. Their analysis covered data between 2007 to 2014 and found that patients did indeed substitute medical marijuana for FDA-approved prescription drugs in these states.

So with all of these benefits to society, who could possibly be against legalization?

Indeed, alcohol and pharma groups have been quietly backing anti-marijuana efforts across the country. Besides Insys, the Arizona Wine and Spirits Wholesale Association gave one of the largest donations to the state’s anti-legalization campaign when it paid $10,000 to Arizonans for Responsible Drug Policy. And the Beer Distributors PAC recently donated $25,000 to the Campaign for a Safe and Healthy Massachusetts, making it the state’s third-largest backer of the opposition to recreational cannabis.
Purdue Pharma and Abbott Laboratories, makers of the painkiller OxyContin and Vicodin, respectively, are among the largest contributors to the Anti-Drug Coalition of America, according to a report in the Nation. And the Pharmaceutical Research and Manufacturers of America, considered one of marijuana’s biggest opponents, spent nearly $19m on lobbying in 2015.

The people most responsible for the opiod epidemic and alcohol poisoning, along with Mexican drug cartels, are against legalization.