Stephen Giblin on Just Security

Are there any cases that challenge the validity of deporting someone resulting in their imprisonment in El Salvador even though the deportation itself may be proper? My limited understanding of deportation is removal from the country and not “rendition” to a country with which the deportee has no previous connection. In other words, what is the legal basis for sending purported Venezuelan gang members to a prison in El Salvador even if removal itself is legal either under immigration law or the Alien Enemies Act?