system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Obamacare is facing another Supreme Court ruling, the second in 4 years. Why are these cases reaching the Supreme Court?
gpt
In this case, there was a circuit split. Two circuits in the United States, the 4th Circuit (*King v Burwell*) and the D.C. (*Halbig v Burwell*) Courts of Appeals came to opposite decisions regarding the same portion of a federal law.

As a result, the Supreme Court decided to step in and settle the issue for all circuits, by issuing a writ of certiorari. Technically, only the King v Burwell case is going before the Supreme Court, but they'll both be affected.