A key federal lawmaker has suggested that Congress should hold hearings on Washington DC’s new recreational marijuana measure, saying such issues should be left up to local governments.

Ron Johnson, a Republican senator from Wisconsin who is set to take over the committee tasked with oversight of Washington DC, said while he doesn’t personally support marijuana use, local lawmakers should decide whether to legalize cannabis. His counterpart in the House, Jason Chaffetz, a Republican from Utah, is opposed to marijuana outright.

Johnson hasn’t taken a position on whether he believes recreational marijuana should be allowed in the District of Columbia; rather, he wants to examine how legalization is playing out in other states.

Washington DC voters legalized recreational marijuana use earlier this month, but Congress has the power to overturn the law.

A report last week found that a handful of influential Republican senators have little appetite or interest in blocking the measure.