An immigration rule the Biden administration touts as a “cornerstone” of its border policy is not having the effects on the border crisis that its creators hoped it would.

The screening standards attempt to identify weak claims for protection, including race, religion, and political opinion. The rule, originally declared a success, was implemented after the Biden administration lifted a pandemic-era asylum restriction in May, and officials hoped it would slow down the flow of illegal immigrants. Agents are supposed to conduct screenings before agents in the processing centers prepare documents for the immigration court, but due to staffing shortages, they’ve only occurred in a fraction of arrests.