Abolitionists were not an extreme position in the north. The abolitionist party had just won the popular vote in every single northern state. Bar none. Therefore it stands to reason that a majority of the population in the north did not consider abolition to be a disqualifying position. 40% of the US population in total had voted for a candidate who was explicitly pro-abolition, just not pro immediate abolition.
Yes Lincoln didn't declare emancipation the second the war started. The still doesn't mean it wasn't a war against slavery. The south started the war! They were the ones who declared secession and fired on federal troops. They did so because they feared lincoln would abolish slavery, maybe not today, maybe not tomorrow but soon and for the rest of their lives!
Lincoln and the abolitionists believed that the issue could take the backburner at first. This is hardly surprising, they had a goddamn war to win! It doesn't mean that they didn't move to solidify the abolitionist position early, with for example the move to abolish slavery in Delaware.
A) He only got elected because he promised not to touch slavery where it existed. Yes abolishionists were a minority and extremist and highly outspoken group.
No he did not. No they were not. They were a mainstream group that won the election.
"A house divided against itself cannot stand."
I believe this government cannot endure, permanently half slave and half free.
I do not expect the Union to be dissolved -- I do not expect the house to fall -- but I do expect it will cease to be divided.
It will become all one thing or all the other.
Either the opponents of slavery, will arrest the further spread of it, and place it where the public mind shall rest in the belief that it is in the course of ultimate extinction; or its advocates will push it forward, till it shall become alike lawful in all the States, old as well as new -- North as well as South.
This is the best known passage from the best known pre-bellum speech by Lincoln. One simply can not state that he was not an abolition or that he didn't campaign on eventual abolition.
Lincoln didn't promise immediate emancipation. However long term emancipation was his stated goal. He merely wished to bring it about peacefully if possible, a possibility that the south rejected.