In a hugely significant unanimous decision Monday, the Supreme Court ruled that a documented immigrant convicted of two minor drug-possession crimes will not face mandatory deportation. The ruling could drastically alter implementation of a controversial 1996 law that limited discretion for immigration judges and helped drive rising deportation numbers. Plaintiff Jose Angel Carachuri-Rosendo had come to the U.S. in 1983, when he was just 5 years old, and had become a permanent resident. A lower court ruled that he was subject to mandatory deportation under the 1996 law as a result of two minor drug-possession offenses, one for marijuana and the other for a single tablet of Xanax, an anti-anxiety prescription drug often used recreationally. Monday’s Supreme Court decision overturns that ruling and, in doing so, gives immigration judges the discretion to weigh the unique factors in many more deportation cases. Carachuri-Rosendo, who is married to a U.S. citizen and has a U.S. citizen child, would have been one of close to 100,000 non-citizens deported annually as a result of criminal convictions (rather than for civil visa violations). The majority of those 100,000 are deported as a result of the 1996 immigration bill, which created a new category of crimes–called “aggravated felonies” in immigration nomenclature–that trigger mandatory deportation. Aggravated felonies, however, include convictions that are considered neither aggravated, nor felonies in normal criminal law. And it’s believed that the bulk of those deported for them are permanent residents like Carachuri-Rosendo.