Oklahoma voters on Tuesday rejected a ballot measure that would have legalized recreational marijuana use by people over the age of 21, a setback for advocates who have seen the conservative state embrace access to the drug for medicinal purposes.

Across Oklahoma, 2,890 licenses have been approved for medical marijuana businesses. Oklahoma City, the state capital, is home to more than 400 dispensaries.

But as of Tuesday night, in a state where 10% of residents own a medical marijuana card and with 90% of ballots counted, 63% of Oklahoma voters rejected the proposal to legalize recreational use.

Despite growing support among younger Republicans, voters in a number of conservative-dominated states have recently blocked efforts to expand legalization beyond the 21 states that currently allow recreational use. Across the US, 37 states approve medicinal use.

In 2018, Oklahoma voters approved the expansion of medical marijuana by a 14-point margin. But the Republican governor, Kevin Stitt, other politicians and law enforcement groups have pushed back against the expansion of recreational use. Last year, state lawmakers approved a moratorium of new medical marijuana business licenses for two years.

Legalization supporters have pointed to tax revenue that could come from recreational use. But they worried low turnout would hamper their efforts.

Ryan Kiesel, a spokesman for the Yes on 820 campaign, told the New York Times the state needed to legalize marijuana, given residents without…