A federal judge ruled Monday that the Trump administration can resume sharing location data about undocumented immigrants receiving public health insurance benefits with Immigration and Customs Enforcement, starting next month.

U.S. District Judge Vince Chhabria’s ruling is a victory for President Donald Trump’s mass-deportation agenda as it allows ICE to use Medicaid data in deportation cases beginning Jan. 6. The agency had been blocked from doing so for months amid a legal challenge from blue states.

“The sharing of such information is clearly authorized by law and the agencies have adequately explained their decisions,” Chhabria wrote in a seven-page order.

The decision marks a significant setback for California Attorney General Rob Bonta and 21 of his Democratic counterparts, who sued in July to prevent the Trump administration from using Medicaid data obtained from the Department of Health and Human Services to target immigrants.