In a 5-4 decision, the Supreme Court has ruled that same-sex couples across the country have a constitutional right to marry, regardless of what state they live in. This brings marriage equality to all of the states where same-sex marriage bans were still in place or still being enforced to some extent: North Dakota, South Dakota, Nebraska, Kansas, Texas, Missouri, Arkansas, Louisiana, Mississippi, Alabama, Georgia, Tennessee, Kentucky, Ohio, and Michigan. The precedent would also apply to U.S. territories, including Puerto Rico.
The decision in the case (Obergefell v. Hodges), unsurprisingly written by Justice Anthony Kennedy, relies on the Due Process Clause of the 14th Amendment, which states, “No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor hall any State deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.” If states allow people to marry people of the opposite sex of their choice, they must allow people to make the same choice for spouses of the same sex.
More analysis to follow.