Oklahoma voters on Tuesday narrowly approved a ballot measure to extend Medicaid to tens of thousands of poor adults, making their state the first to expand government-backed health insurance during the pandemic.

The vote, which passed with 50.5 percent support, also throws a wrench in the Trump administration’s plan to make Oklahoma the first state to receive its permission to cap Medicaid spending, a longtime goal of conservatives hoping to constrain the safety-net entitlement program.

Ballot organizers said the coronavirus crisis would help make their case for expanding Medicaid in the deep-red state. The average number of new cases in Oklahoma has more than doubled in the past month, and the state reported a record 585 new infections on Tuesday.