That more or less is exactly what happened in the Civil War era. Before the war the abolitionists were a perpetually outvoted minority who were regarded as radical fanatics and even would-be proponents of theocracy. If it hadn’t been for the political circumstances of the attempt at secession, chattel slavery might have continued into the 20th century. Equality for the former slaves was as much about the cynical calculation that every newly enfranchised freedman was a guaranteed Republican vote as it was about any ideals of respecting rights. It required making ratifying those amendments a condition for the defeated southern states to have their congressional representation restored to meet the supermajority requirements for amendment; it would never have happened if the slave states had had any real choice in the matter. And we saw exactly how devoted the north was to championing civil rights once Reconstruction ended and the southern states were no longer conquered provinces. When African-Americans began the Great Migration out of the South after World War One, the North actually de-liberalized where civil rights were concerned; this was the era when the new Ku Klux Klan was founded in honor of the southern “night riders”. Apparently northern whites had always been in favor of freedom and rights for blacks living somewhere else.
The Loving decision was one of the fait accomplis handed down (imposed?) by the Supreme Court of that era. It would have been a much harder sell if for example it had to have been enacted by federal legislation. After the court decision it would have required a constitutional amendment to specifically reverse it, and bigotry didn’t have THAT level of support. But imagine if something like the Loving decision had happened in 1905; maybe there WOULD have been a constitutional amendment overturning it.
My point is simply that God does not send angels down out of Heaven bearing flaming swords to defend the righteous. What comes to pass especially in the realm of politics and law is ultimately based on pure power. The USA will ultimately be only as just as the People demand that it be, and the People are far from perfectly just. Currently something like a 57% majority is fighting against a 43% minority, and while the majority has a mandate it does not have an overwhelming mandate. It in fact does take well over half the population, more like two-thirds, to agree to respect the rights of a minority. Liberals would like to think that they are strong enough to shout down the bigots; but they’re not.