Federal agents who usually hunt down child abusers are now cracking down on immigrants who live in the U.S. illegally.

U.S. border officials are using more aggressive tactics at ports of entry, scrutinizing green card and visa holders who have expressed political opposition.

As U.S. President Donald Trump pledges to deport “millions and millions” of “criminal aliens,” thousands of federal law enforcement officials from multiple agencies are being enlisted to take on new work as immigration enforcers, pulling crime-fighting resources away on other areas − from drug trafficking and terrorism to sexual abuse and fraud.