One of the most conservative judges in the US Supreme Court on Monday said federal laws against the use of marijuana have been undermined by the recent hodgepodge of federal policies on it.

Judge Clarence Thomas wrote, “A prohibition on interstate use or cultivation of marijuana may no longer be necessary or proper to support the federal government’s piecemeal approach,” according to NBC News.

Recently, the Supreme Court declined to hear the appeal of a Colorado medical marijuana dispensary that was denied federal tax breaks that other businesses are allowed.

While 36 states now allow medical marijuana and 18 also allow recreational use, federal tax law does not allow marijuana businesses to deduct their business expenses.

Thomas’ comments are in light of those aforementioned events. 

Additionally, he said the Supreme Court’s ruling in 2005 upholding federal laws making marijuana possession illegal may now be out of date.

“Federal policies of the past 16 years have greatly undermined its reasoning,” he said.

“The federal government’s current approach is a half-in, half-out regime that simultaneously tolerates and forbids local use of marijuana.”

Thomas argued that if the business expenses aren’t allowed to be deducted, “a business that is still in the red after it pays its workers and keeps the lights on might nonetheless owe substantial federal income tax.”

Meanwhile, the Justice Department has instructed the nation’s federal prosecutors not to pursue cases against marijuana businesses that follow state law.

The US Congress has also prohibited the DoJ from spending federal money to prevent states from carrying out their own laws.

However, the IRS continues to enforce its own rules against growers and dealers.