How does regional opposition to same-sex marriage today mirror regional opposition to interracial marriage in the previous century?

Answer 1

So-called "anti-miscegenation laws" that outlawed interracial marriage were justified by religious arguments taken from interpretations of Bible passages. The same is true of anti-gay marriage laws.

Anti-miscegenation laws were either never passed or repealed before 1887 in the Northeast. The Northeast currently represents the largest cluster of states that have legalized same-sex marriage.

The Deep South held on to its laws against interracial marriage until they were declared unconstitutional by the US Supreme Court in 1967 (Loving v. Virginia). The Deep South, together with the Midwest, is currently a major cluster of states that have banned same-sex marriage both by constitutional amendment and by statute.

Three different times amendments to the US Constitution were proposed to ban interracial marriage in the entire country. These were proposed by legislators from Missouri, Georgia and South Carolina. A federal anti-gay marriage amendment has been discussed and legislators from those states would likely be among those to support it.

Generally, the list of states that never had anti-miscegenation laws and those that were among the first to repeal them in the 19th century contains the names of states which have legalized same-sex marriage in the 21st century.

Interestingly, Massachusetts enacted a law in 1913 to prevent residents of other states from circumventing anti-miscegenation laws by coming to marry in Massachusetts. That very same law was actually used against out-of-state same-sex couples until 2008 when it was repealed.