A would-be Republican presidential nominee has changed his mind on marijuana. Sen. Ted Cruz said he supports Colorado’s state rights to keep marijuana legalized without federal interference during an interview with Fox News host Sean Hannity at Thursday’s Conservative Political Action Conference (CPAC).

“I actually think this is a great embodiment of what Supreme Court Justice Louis Brandeis called ‘the laboratories of democracy,’” Cruz said. “If the citizens of Colorado decide they want to go down that road, that’s their prerogative. I personally don’t agree with it, but that’s their right.”

Cruz’s comments at CPAC bring him in line with a number of prominent Republican presidential candidates, including former Texas Gov. Rick Perry, Sen. Marco Rubio and Sen. Rand Paul, who have all said they believe the federal government should not interfere in states where marijuana has been legalized. Yet Cruz’s comments are also a departure from a long-held position. Earlier this month, Cruz blasted President Barack Obama in an interview in Reason magazine for refusing to override Colorado’s state laws, calling Obama’s selective enforcement of federal law a “dangerous precedent” that was “dangerous to liberty.”

The senator’s change of heart was greeted warmly by marijuana advocacy groups. “We hope to work with Sen. Cruz and his Republican colleagues in Congress to develop legislative solutions to the problems created by federal marijuana prohibition,” Don Murphy, a policy analyst at the Marijuana Policy Project, said in a statement. “We need to guarantee states have the freedom to adopt and implement the policies that work best for them.

“Marijuana policy reform is, at its heart, a conservative issue,” Murphy wrote. “This is a matter of Federalism, the 10th Amendment, and state autonomy, which are core conservative priorities. Marijuana prohibition is a failed federal government policy, and rolling it back should be on the agenda of every principled Republican lawmaker.”

Cruz has admitted to using marijuana as a teenager. According to a spokesman, he has characterized past uses of the drug as a “mistake.”