That was a great read, thanks.
I think in making her excellent points, she undersells the 1860 Northern coalition's makeup w/respect to aversion to slavery, and not just slave owners. With slavery being so intertwined into the fabric of the country, it was something that was almost impossible to peacefully unwind. There isn't a good analogy for it, but abolition was as radical an idea as something like banning the use of cheap foreign labor while giving all illegal immigrants citizenship, at least for its scale and impact (and the label of "abolitionist" was something akin to labeling an American a "communist" during the Cold War). Except more radical than all of that, probably. Yet anti-slavery people (not just anti-slave-economy people) made up a real, live, morally influential part of the new party, without which it would probably not have won. A lot of antislavery beliefs were held down by the political impossibility of the proposal. It was a question of pragmatism vs. idealism for many, especially because everybody knew the Union was at stake.
I guess the difficulty of that moral stand lies somewhere between defying Nazi Germany and being a Never-Trumper. I don't think I would have been an abolitionist myself. Probably a Free Soiler who talked about how bad slavery was, and opposed it, but wanted to pick a fight at stopping the expansion of slavery rather than forcing the civil war that came anyway.
Imagine knowing that something is morally reprehensible and must be stopped, yet having no recourse to end it short of civil war, and trying to compromise- only to be forced into war anyway. That's the position every morally-forward but pragmatic person in America was in.