So you are suggesting he was traumatized by all the wicked slavery going on in Indiana at the time? (Been years since I've read a Lincoln biography.)
Slaveholding wasn't Lincoln's culture. And do you automatically support things that you think wrong because they are part of you "own culture"?
When it's part of your culture, it doesn't occur to most people to regard it as wrong. This sort of Oikophobia is normally a characteristic of Liberals.
And what's with the compulsion to ascribe opportunistic motives to people you disagree with or don't like anyway?
Because the evidence supports it. Lincoln repeatedly said he would do nothing to interfere with Slavery. For a year and a half, he was going to do nothing about slavery, but suddenly he decided he needed to do something about slavery, even though he also repeatedly said he had no legal authority to do anything about it.
Flip Flopping is a sign someone doesn't really hold strong principles about something. This tends to make you believe that what they say is an artifice to help their political career.
Lincoln went south on a trip to New Orleans and it's said that he was revolted by slavery. More to the point perhaps, he'd worked his way up from poverty in a free society and economy and the idea of slavery just didn't appeal to him.
When it's part of your culture, it doesn't occur to most people to regard it as wrong. This sort of Oikophobia is normally a characteristic of Liberals.
You have to be radically polarized to believe that things you would otherwise think wrong are right because they are part of your culture. Such an view reflects the relativism that is also said to be characteristic of liberals.
But it should be clear by now that slave states and free states were evolving very different cultures. Lincoln was being true to the best side of his free state culture by opposing the expansion of slavery.
Lincoln repeatedly said he would do nothing to interfere with Slavery.
Lincoln repeatedly said he thought slavery was wrong, but wasn't going to do anything about it where it existed. He recognized that support for slavery was too strong there, and support for abolition would lead to disunion. It didn't do any good, as even his position was unacceptable to the slave states.
Flip Flopping is a sign someone doesn't really hold strong principles about something. This tends to make you believe that what they say is an artifice to help their political career.
"Flip-flopping" would be saying "Slavery is great!" one day and "Slavery is awful!" the next. Recognizing that something is not good and that little can be done about it doesn't count as "flip-flopping." What's possible in politics changes over time. What's desirable can also change.
Think of Nixon and China. Nixon wasn't saying Mao was bad yesterday and good today. He was saying, we can now achieve our long-term goals better with China inside the world political system than with China outside it.
I realize that Richard Nixon isn't the best example to cite when talking about political principle. Maybe Churchill is better. He recognized that Stalin was evil, but that he would have to cooperate with Stalin to ensure Britain's survival and Hitler's defeat.
It's easy to be smug about "principles" when you don't have responsibility for anything. It's easy to be inflexible when what you say and do won't have any possible effect on what happens in the world.