Degeneration of society is being accepted on the legal level.
The fundamental core of the American societal experiment was a separation from an overbearing authority in the pursuit of individual liberties. It seems clear to me that freedom to marry who you want, where you want, and how you want would be pursuant to that eidolon. Now, you don't have to agree with that core tenet, but on an empirical level _that rejection_ would be degeneration: a fall from first principals (which might not be a bad thing depending on your normative frameworks - I'm inferring that you're not a fan though).
I had a religious studies professor make a - reasonably evidenced - claim that the whole 'seperation of church and state' stuff during the revolution was widely understood to basically be lip service. The vast majority of Americans were under the impression that they were starting a Christian country with a Christian government. That same professor made the - less evidenced - conclusion that the implicit divide between that expectation and the legal reality has underscored a considerable portion of American political turmoil to date.
This is nonsense. Humanism is exactly about that.
Primarily state marriage is about sharing privileges and duties before the law.
Edit: didn't mean to accuse you of anything, but to offer a different perspective to how the situation could be viewed
I don't think this will cause a degeneration of society. If anything, the American export of "everything is us versus them" tribal mentality to politics and society is much worse. Granted, some of that always existed but I feel like it was waning until social media and exposure to American politics started reviving it. Please don't let it influence your daily life like that
The "Don't tread on me" side of the population - I don't think "the right" is the correct term here - tends to be want left alone by overreaching governmental busybodies. They also tend to be more on the traditional side of societal norms - again not something which is limited to "the right", there are plenty of traditional left-wing thinkers who did not like the "free love" movement of the 60's and don't like it still - so are not wont to go for polyamory unless they happen to be Mormons and talk about polygyny.