In what way does the National government have power over the issue of gay marriage?
Insofar as the federal government is concerned, marriage is not about an emotional or spiritual or sexual union, but about rights and duties of couples as financial, even commercial entities. A traditional marriage has, as part of its ritual and as part of its financial contract (including legal rights and responsibilities of offspring), a legal registry in a courthouse somewhere. But same-sex partnerships have no such legal registry and therefore no such legally acknowledged contract. Some states have repaired this problem by legalizing these partnerships through a "marriage" registry, that then gives that couple states' rights--hospital visits, adoption privileges, tax exemptions, etc. Federal "registry" would give same-sex couple national privileges and responsibility, and would eliminate awkwardnesses at state borders. A same-sex couple would be treated so in federal taxation also. The controversy is really linguistic--does the word "marriage" belong to religions? Or is it simply a word in the English language meaning any joining of two or more elements?