If someone supports gay marriage they have no basis for opposing polygamist or incestuous marriages outside of how it subjectively makes them feel. Marriage is historically a religio-cultural institution. Without that context there can be no restrictions that don't also violate foundational secular values such as personal freedom. Secularity and modernism gatekeeping marriage is a hilarious mental gymnastics routine. These days marriage is just something to keep lawyers in business anyway. The government should just get out of the marriage business entirely at this point.
Then by OPs logic it would follow that the oppressed are only in that position because they are weak. (e.g. not temporarily disenfranchised revolutionaries) If they were "strong" they would be in the oppressors position.
That's possible with a confederate structure like the EU which maintains certain human rights standards while respecting sovereignty to a degree. Obviously if states were totally sovereign they could do whatever they want unless they were faced with undue external force from other countries (e.g. states).
Yeah but if it's a universal truth then it transcends all categories. The stronger nation topples the weaker while the bully dominates others in the schoolyard. Therefore any semblance of egalitarianism or equality is artificial and sustained only by the threat of force. This force only exists if there are enough intelligent and strong people in the society that also agree to the social contract in enough numbers that it won't collapse or be conquered by an outside force. (e.g. Brute force is all that matters)
This point is often dismissed but the United States really does need "a divorce". At least a return to pre-civil war state sovereignty where incompatible ideologies can each find their home.
AIPAC