Justice Anthony Kennedy, seen as a pivotal swing vote in the case, wrote the majority opinion. All four justices who voted against the ruling wrote their own dissenting opinions: Chief Justice John Roberts and Justices Antonin Scalia, Clarence Thomas and Samuel Alito.
Update at 10:37 p.m. ET: More On The Ruling, And Obama's Reaction
"The ancient origins of marriage confirm its centrality, but it has not stood in isolation from developments in law and society," Kennedy wrote. His opinion sketches a history of how ideas of marriage have evolved along with the changing roles and legal status of women.
Comparing that evolution to society's views of gays and lesbians, Kennedy noted that for years, "a truthful declaration by same-sex couples of what was in their hearts had to remain unspoken."
"The nature of injustice is that we may not always see it in our own times," Kennedy wrote after recounting the legal struggles faced by same-sex partners.
In his dissent, Roberts wrote that the court had taken an "extraordinary step" in deciding not to allow states to decide the issue.
Continue Reading at .... http://www.npr.org/sections/thetwo-way/2015/06/26/417717613/supreme-court-rules-all-states-must-allow-same-sex-marriages