On Tuesday morning, the Colorado Supreme Court heard the opening arguments in a case that could set a nationwide precedent when it comes to the use of marijuana in states that have legalized the drug.

Although both medical and recreational marijuana has been legalized in Colorado, federal law still prohibits its use. As a result, 35-year-old Brandon Coats was fired from his job for using medical marijuana in 2010. Now he is suing his former employer, the Dish Network, reports WWMT-TV.

Coats, a registered quadriplegic medical marijuana patient, says that his doctors recommend that he smoke weed in order to help ease his violent muscle spasms that began after he got into a bad car accident when he was 16 years old.

However, he was terminated from the Dish Network after he failed a random drug test that found THC in his system.

Attorneys representing the satellite service provider argue that the employer had the right to fire him based on the company's zero-tolerance drug policy, which prohibits employees from using alcohol or illegal substances. Because pot is still illegal federally, the defense argues that medical marijuana is not a lawful activity, despite state law.

"Mr. Coats was never accused or suspected of being under the influence and received satisfactory performance reviews all three years," said Coats' attorney Michael Evans in court, according to the Huffington Post.

"He was fired after an unknown type or amount of THC was found after a mouth swab test. Dish knew he was a medical marijuana patient. The mere presence of THC is not proof of impairment," said Evans.

However, Meghan Martinez, the attorney representing Dish Network, argued that "it doesn't matter if he was impaired or not. It's a violation," reports the Denver Post.

"We are arguing that it is lawful," Evans said. "There is a distinction between a state saying 'This is lawful, it's permitted, we allow it,' and the state [...] saying 'You have a constitutional right to do it.' The state is allowed to create laws so long as it does not create a positive and irreconcilable conflict [with federal law]."

On the other hand, Martinez disagreed based on federal legislation.

"When you look at [Colorado's] medical marijuana act, there is nothing in that statute that says that this is lawful activity," she argued. "The MMA needs to be read much more narrowly. It's an affirmative defense, an exception to state criminal laws, and that's it. Marijuana is still unlawful, we know that from the Controlled Substances Act [of 1970]. The CSA has THC and marijuana as controlled substances that are illegal under the federal law."

The decision in this case could clarify cannabis' place in the law and determine whether Coloradans have a right to use marijuana.

"The eyes of the nation are watching as Colorado carries out an experiment by relaxing state laws on marijuana," said the Colorado attorney general's office wrote in a statement filed on behalf of Dish Network.