[JURIST] A judge for the US District Court for the District of Oregon [official website] on Monday struck down [opinion, PDF] Oregon’s voter-approved ban on same-sex marriage, saying that the ban could not be enforced because it unconstitutionally discriminates against same-sex couples. In his opinion, Judge Michael McShane wrote that because the laws discriminate on the basis of sexual orientation, the laws violate the Equal Protection Clause of the Fourteenth Amendment [text] to the US Constitution. State officials declined to defend [AP report] the ban prior to the ruling and said they would not be appealing Monday’s decision. With the lift of this ban, Oregon joins a list of 13 states that have seen legal victories for same-sex marriage advocates since a Supreme Court ruling last year overturned part of a federal ban.

The heated debate over same-sex marriage [JURIST backgrounder] is one of the most polarizing issues currently facing the American legal community. Earlier this month McShane rejected an attempt [JURIST report] by the National Organization for Marriage [official website] to intervene in litigation to defend the state’s same-sex marriage ban. Litigation is currently ongoing in numerous state and federal courts, including Alaska, Arkansas, Idaho, Indiana and Georgia [JURIST reports], among others. A challenge is expected to South Dakota’s same-sex marriage ban, which would leave North Dakota and Montana as the only states [TIME report] whose same-sex marriage bans have not been challenged in court.