Just so we’re clear: yes, in this analogy, patriarchy is Jar-Jar Binks.
The US constitution is a tangle of grand Enlightenment ideals and messy post-monarchic politics. American history is, in some senses, the long and painful process of rescuing the ideals from the politics.
We’ve been mucking about with the definition of marriage for thousands of years. Letting same-sex couples in on the action is one of the least weird changes we’ve ever made.