Complex sentence: On June 26,2013, Section 3 of DOMA was declared unconstitutional by the U.S. Supreme Court in "United States v. Windsor", citing the Due Process Clause of the Fifth Amendment.
Split into simpler sentences: On June 26,2013, Section 3 of DOMA was declared unconstitutional by the U.S. Supreme Court in "United States v. Windsor" (2013). The ruling cited the Due Process Clause of the Fifth Amendment.