Starting on Thursday, getting caught by police in Washington, DC with a bag of weed, a blunt, or a bong with residue will warrant only a ticket and a $25 fine — for now, at least.

After a mandatory 60-day Congressional review, a District City Council law decriminalizing possession of less than an ounce of marijuana took effect at the stroke of midnight. Apart from Washington and Colorado, where marijuana was legalized last year, DC’s legislation is perhaps the most progressive drug law in the nation, dropping the most common marijuana charges to civil offenses.

The US Constitution grants Congress near total control of the District, and despite allowing the creation of a DC mayor and City Council in the Home Rule Act of 1973, the Senate and House still maintain jurisdictional oversight over changes to any laws or legal statutes in the area.

Passage of the bill was closely linked to concerns over racial profiling and civil rights. In the district, 9 out of 10 people arrested for marijuana possession are black. A Washington Post poll earlier this year found that 8 out of 10 residents supported legalizing or decriminalizing marijuana, and the City Council passed the bill with overwhelming support.

“It is a matter of social justice that we end the criminalization of marijuana possession,” DC councilman Tommy Wells, one of the bill’s sponsors, said in a statement. “The disproportionate number of marijuana-related arrests of African-Americans in DC has caused a significant public harm, impacting future employment and education opportunities.”

The city’s police chief had in recent weeks distributed a circular to officers instructing them on the details of the new law. Smoking in public remains illegal, but metropolitan police will not be able to use the odor of marijuana or even the presence of paraphernalia and up to an ounce of pot as cause to arrest suspects or search them further. If they violate the law and uncover a crime after an unwarranted search, local courts could rule that the evidence gathered is inadmissible.

“If people initiate the search against someone’s will and odor is the pretext, we hope judges will look at this as a violation of your 4th Amendment rights,” Seema Sadanandan, program director at ACLU of the Nation’s Capital, told VICE News. “But that remains to be seen.”

There’s reason to be wary. New York decriminalized minor possession in 1977, but due to legal loopholes and the use of controversial stop-and-frisk tactics, NYPD officers still arrest over 50,000 people — 85 percent of whom are black or Hispanic — every year for possession.

Enforcement is further complicated in DC because the new ordinance doesn’t apply to federal law enforcement or violations that take place on federal property. Get caught with pot on the National Mall and you’ll be handcuffed and hauled away.

Although it has been implemented, the law is currently in a sort of limbo, however, as the city awaits the outcome of Congressional Republican efforts to interfere with the council’s decision. Last month, Congressman Andy Harris (R-Md.) added an amendment onto the 2015 House spending bill that would prevent DC’s local law enforcement from funding the implementation of the council’s bill.

In addition to a review period, Congress has oversight of the District’s annual budget, covering everything from medical care to housing. Harris, who is a doctor, believes decriminalization will encourage use among teens and harm “developing brains.” Though studies have suggested that early marijuana use might adversely affect the brains of teenagers, Harris’s argument does not address the civil rights concerns of the bill’s proponents.

It’s also unclear that decriminalization will result in an increase in use. This has not been seen in places where the policy has been attempted in earnest, such as Portugal.

DC Mayor Vincent Gray responded to Harris’s amendment to the spending bill by calling for a boycott of his district, which includes popular summertime destinations along Maryland’s coast.

Maryland actually decriminalized possession of up to 10 grams of marijuana in April, a month before DC passed its measure, leading Gray to assail Harris’s position as “hypocrisy at its worst.”

The Congressional amendment undercutting DC’s law was approved by the House Appropriations committee, and the House passed the spending bill on Wednesday. But it’s unclear if the provision will survive the horse-trading that will occur as the House and Senate reconcile different versions of the spending bill. Staff close to the Senate Appropriations Committee told VICE News it was common for such tacked-on amendments to be discarded.

President Obama earlier this week appeared to put the kibosh on Harris’s effort by indicating that he would veto any bill emerging from Congress that included the provision. In a statement that maligned Congressional meddling in DC abortion and harm-reduction policies, the White House said that the Harris amendment “undermines the principles of States’ rights and of District Home Rule.”

Harris is stubbornly undeterred.

“DC is not a state,” Erin Montgomery, Harris’s press secretary, told VICE News after the bill took effect. “The US Constitution expressly gives Congress the right to legislate over DC.”

“I think that decriminalization equals acceptability,” she added. “No good can come from this.”

Harris’s office would not answer questions concerning the racial disparity of arrests in in the capitol.

“When you have 91 percent of all arrests being of African-Americans, it seems like there are systemic issues at play in the DC Metropolitan Police Department,” Malik Burnett, policy manager at the Drug Policy Alliance’s DC office, told VICE News.

Washington, DC, currently has nearly twice the rate of arrests for marijuana possession as New York. Sadanandan regards DC’s decriminalization initiative foremost as an effort to diminish the striking number of detentions.

“The real issue isn’t marijuana, the real problem is aggressive enforcement of low-level crimes,” said Sadanandan.

While Republicans seem concerned that decriminalization would somehow turn the city into a weed Mecca, another Republican amendment might make it a scene out of Grand Theft Auto. In addition to Harris’s intervention, Congressman Thomas Massie (R-Ky.) included a provision in the House’s spending bill that would gut the District’s gun restriction laws. They were already weakened in 2008 by a Supreme Court ruling that ended its ban on handguns. Now Massie wants to eliminate funding for the Firearms Registration Amendment Act of 2008, the Inoperable Pistol Amendment Act of 2008, the Firearms Amendment Act of 2012, and the Administrative Disposition for Weapons Offenses Amendment Act of 2012.

“It is time for Congress to step in and stop the DC government’s harassment and punishment of law-abiding citizens who simply want to defend themselves,” Massie declared.

As of today, the city’s citizens can at least avoid harassment and punishment from DC police for possession of marijuana.

Follow Samuel Oakford on Twiiter: @samueloakford