"Individual with liberty and justice for all" is what our nation's Pledge of Allegiance to the United States is. Everybody should be protected by law when they wish to marry someone.
Yes, some people don't agree with it, but not everyone agrees with every religion but that is protected in the very first amendment.
This is a human rights issue, humans have the right to marry who they wish to, even if it means the federal government must override the reserved powers of state to marriage and divorce laws.