The Supreme Court decided today in Lopez v. Gonzales that a state drug possession offense that is defined as a felony under state law, but which would be a misdemeanor under the federal Controlled Substances Act is not an "aggravated felony" for the purpose of federal immigration law, 8 U. S. C. §1101(a)(43)(B). Classification as an "aggravated felony" means the defendant will be deported upon release from prison; other offenses may also create a risk of deportation, but the "aggravated felony" classification is particularly rigid.

Prosecutors and defense lawyers alike need to understand the immigration consequences of convictions in lower-end felony cases (and even some misdemeanors), which unfortunately means understanding a complex, badly written, and sometimes illogical statute. When the defendant is a legal permanent resident alien (i.e., has a "green card"), the immigration consequences may be more important to him than the direct penal consequences and may determine his willingness to accept a plea bargain.

Pete Yost of AP reports here.

Coincidentally, the Court heard oral argument on another such case today, Gonzales v. Duenas-Alvarez. The transcript is available here. Update: SCOTUSblog's summary of the argument is here.