NPR: The long, costly, and complicated road to marriage equality

Same-sex marriage supporters wear "Just married" shirts on June 26, 2015 in San Francisco. (Photo: Justin Sullivan/Getty Images)

Americans’ views on same-sex marriage have undergone a revolution in a few short decades.

Public opinion on the issue swung so swiftly and decisively — and so little uproar resulted once it was legal nationwide — that one might easily assume the…