The agency responsible for immigration enforcement has aggressively revived and expanded a decades-old program that delegates immigration enforcement powers to state and local law enforcement agencies.

Advocacy groups and immigration attorneys warn that Biden’s overall success could be limited if he’s unable to tackle another problem that has been growing for years: the ever-growing case backlog in federal immigration courts. Without addressing the backlog, they say, Biden's mission of achieving a fair and equitable immigration system won't be complete. That’s more than double the 542,411 cases pending when Donald Trump took office in 2017. The backlog grew under Trump despite the former president adding hundreds of immigration judges. Leaders from both parties, including Vice President Kamala Harris, have supported appointing even more immigration judges.