Lincoln was a lot of things, but stupid wasn't one of 'em. He was an admittedly self taught man and in many ways was extremely wise, yet almost "common" in many of his mannerisms too, which made him endearing to many people.

He also was an immaculate and crafty politician who presided over one of the saddest times in our history, while also enduring some of the most troubling personal issues known to any man who ever lived on top of that.

I do think he absolutely believed in his righteousness on the issue of slavery and utilized it as a tool to unite the north against the south, while effectively down playing the issues the southern states really held forth as their basis for secession.

Indepth study of how he turned the tide in congress to adopt the freedom of the slaves legislatively, when the bulk of the legislature was actually initially against it reveals all the arm twisting, back room dealings, paybacks/payoffs and all other manner of similar nasty political trickery most everyone knows, yet similarly despises about how politics works.

All that having been said I'd heartily agree he indeed was an opportunist