The Justice Department announced today that they're taking a new look at how to work around mandatory minimum sentencing laws for low-level drug crime.

It's a substantial concession on the part of the Department of Justice.

Then again, the Obama Administration's way of dealing with marijuana has been marked by substantial concessions that have been surreptitiously revoked, oftentime leaving entrepreneurs and patients in the lurch.

In 2008, presidential candidate Sen. Barack Obama told the Medford Mail Tribune of Oregon that he's going to end the conflict between the federal government and states that decide to decriminalize, medicalize, or legalize marijuana within their borders:

"What I’m not going to be doing is using Justice Department resources to try to circumvent state laws on this issue simply because I want folks to be investigating violent crimes and potential terrorism. We’ve got a lot of things for our law enforcement officers to deal with."

It was a compelling argument. Since the Nixon administration declared the War on Drugs, $1 trillion has been spent by the government. The goal: reduce quality, cut supply, reduce drug addiction.

Well, since then, quality has increased almost as quickly as access, and drug addiction statistics have remained rising or stagnant. Great job!

So when the young senator from Illinois indicated he was amenable to at least winding that down, people got hopeful.

When then-President Obama's new Attorney General announced in March of 2009 that the Bush-era raids of medical marijuana dispensaries were over, entrepreneurs breathed a cautious sigh of relief. The ACLU drug law project director told the New York Times that it "seem[ed] to finally end the policy war over medical marijuana."

The Attorney General didn't keep his word, though, and soon the raids began again, more severe than ever before.

In 2012, the Justice Department began marching north up the coast of California shutting down marijuana dispensaries that were legally operating under California law.

It's been tough to be in the business in California. In 2012 the DEA marched north from San Diego to Los Angeles to Oakland to eventually San Francisco, raiding more than a hundred businesses, seizing assets, and shutting the legal marijuana business down in California as much as they could, despite earlier assurances from the President and Attorney General.

Despite the formal raids against upwards of 100 businesses, the Holder's Department of Justice has also figured out a way to solve their marijuana problems without expending police or DOJ resources through the threat of applying asset forfeiture laws to landlords with tenants involved in marijuana.

According Americans for Safe Access, the government is threatening landlords who rent to marijuana businesses with jail time in order to get them to evict their renters:

The DOJ recently sent notices to property owners in California informing the owners that they may face criminal prosecution or asset forfeiture for knowingly renting their property to an MCDC or cultivator.

In what they describe as a "cynical tactic," Justice has avoided going through the motions of a jury trial by intimidating landlords into expelling rent-paying clients.

The reason that places like Colorado have not been hit by the Feds while California has essentially comes down to regulation.

Colorado has a highly sophisticated marijuana regulation regime. First of all, all the dispensaries must be vertically integrated — that is to say, they must grow 70% of the cannabis that they sell. Moreover, the entire industry is heavily monitored by the Colorado Department of Revenue.

Every gram of marijuana is tracked by sophisticated software systems, with regular reporting to the Department of Revenue. Dispensaries can grow up to a maximum of six plants per registered patient. Waste from groweries is destroyed responsibly. The business is very transparent from a regulatory standpoint, which is one reason that the Feds haven't seen it fit to interfere.

California, on the other hand, is a vastly deregulated free-for-all. The state doesn't know where the product even comes from. The state is also a regulatory hodge-podge, with different localities having vastly different ways of handling marijuana.

Medical marijuana dispensaries don't necessarily have the same level of oversight realized in more regulated markets like Colorado. It's not beyond authorities to speculate that marijuana sold in California came from illicit sources like organized crime. As a result, Washington dropped the hammer on California's marijuana industry.

Here's how the President explained the justification for the action against marijuana dispensaries acting compliant with state law in an interview with Rolling Stone:

I can't nullify congressional law. I can't ask the Justice Department to say, 'Ignore completely a federal law that's on the books.' What I can say is, 'Use your prosecutorial discretion and properly prioritize your resources to go after things that are really doing folks damage.'

So when Attorney General Eric Holder says today — much has he did four years ago — that, despite federal law that's on the books, he would ask the Justice Department to not enforce mandatory minimums, you might understand why people may be skeptical.