Have I mentioned that I love Justice Kagan’s writing style. This sentence in Judulang v. Holder is perfect.

This case concerns the Board of Immigration Appeals’ (BIA or Board) policy for deciding when resident aliensmay apply to the Attorney General for relief from deportation under a now-repealed provision of the immigrationlaws. We hold that the BIA’s approach is arbitrary and capricious.

The legal background of this case is complex, but theprinciple guiding our decision is anything but. When an administrative agency sets policy, it must provide a reasoned explanation for its action. That is not a high bar,but it is an unwavering one. Here, the BIA has failed to meet it.

And this easy-to-understand imagery:

Those mathematically inclined might think of thecomparable-grounds approach as employing Venn dia- grams. Within one circle are all the criminal offenses composing the particular ground of deportation charged. Within other circles are the offenses composing the various exclusion grounds. When, but only when, the “deportationcircle” sufficiently corresponds to one of the “exclusion circles” may an alien apply for §212(c) relief.

The BIA gets an F!

That task involves examining the reasons for agency decisions—or, as the case may be, the absence of such reasons. See FCC v. Fox Television Stations, Inc., 556 U. S. 502, 515 (2009) (noting “the requirement that an agency provide reasoned explanation for its action”).

The BIA has flunked that test here. By hinging a deportable alien’s eligibility for discretionary relief on the chance correspondence between statutory categories—amatter irrelevant to the alien’s fitness to reside in this country—the BIA has failed to exercise its discretion in a reasoned manner.

And this headscratching sentence:

Or consider a different headscratching oddity of thecomparable-grounds approach—that it may deny §212(c) eligibility to aliens whose deportation ground fits entirelyinside an exclusion ground.