True, the Northern people wanted the slaves to be free, but they wanted someone else (Southerners) to have to deal with them and live with them and to suffer the threat of genocide from a black rebellion (similar to what happened in Hayti).
I am saying that if the South had threatened to send half the blacks living in the south up to the North to live and to compete for jobs, then the abolitionists would have been 'run out of town' and 'made to shut up' by the protests of other northerners who wouldn't have wanted blacks to be sent up north.
It would have put the spotlight on Northern hypocrisy in a big way. Heck, Northerners didn't even want Catholics up there! Show me a Puritan, a Quaker, a Congregationalist, or a Unitarian, and I don't want to have anything to do with them because they know better than anyone else - they are perfect, and everyone else is a letchurer and sinner.
Get it now?