On the view that marriage is essentially a conjugal union, these legalisation steps mean the deconstruction of marriage. Ross Douthat sums up the threshold: "If marriage can be redefined according to what we desire — that is, if there is no essential nature to marriage, or to gender — then there are no boundaries on marriage. Marriage inevitably loses its power."
This will not be the end of this road; the logic of the revisionist case entails more permutations. The U.S. Chief Justice in dissent pointed out some of these.
I wonder whether all the rainbow bandwagon people right now realise the implications of their sympathising.
I remember reading at university the Marxist theorists that advocated a new front for the revolution in the West given the receding hope of political revolution - to conduct a 'long march through the institutions'. Their idea was to undermine the West by corrupting and subverting its culture. Starting with sexual progressivism, they are now captured the sanctuary of marriage in jurisdictions like the US.
As Douthat says in his NYTimes article, the next step will be to come after the social conservatives, and crush dissent through anti-discrimination actions. The mechanisms are in place. It is not just legal sanction that is on view now, but social endorsement. There is a new sexual orthodoxy taking control and dissent is portrayed as pernicious and prejudiced.
If my government decides to change the legal view of marriage, so be it. I will stick with my adherence to the conjugal view, which has a long history and is in sync with nature and biology. Wisdom, love and courage will be needed in a new social climate.