There's a pretty vigorous discussion thread on my Bachmann post, but I want to follow up with a couple of points. Some folks argued that the fact that Bachmann endorsed the authors in question doesn't inherently mean she shares their distorted view of slavery. This is a mistake, as Ryan Lizza explains that to whatever degree she agrees with each individual point, she certainly agrees with the idea that slaveovers who refused to free their slaves might do so for "benevolent" reasons.
Bachmann's comment about slavery was not a gaffe. It is, as she would say, a world view. In “Christianity and the Constitution,” the book she worked on with Eidsmoe, her law-school mentor, he argues that John Jay, Alexander Hamilton, and John Adams “expressed their abhorrence for the institution” and explains that “many Christians opposed slavery even though they owned slaves.” They didn't free their slaves, he writes, because of their benevolence. “It might be very difficult for a freed slave to make a living in that economy; under such circumstances setting slaves free was both inhumane and irresponsible.”
As a reader pointed out in an email, this was an argument defenders of slavery made not infrequently. Abraham Lincoln quipped that "Although volume upon volume is written to prove slavery a very good thing, we never hear of the man who wishes to take the good of it, by being a slave himself." There's also something oddly selective about a conservative justifying slaveowning on the basis that slaves could not have provided for themselves, while casting social insurance as tyrannical government overreach.