Lincoln, on the complicated intersection between morality and "practical" politics

Found while I fell into a rabbit hole while searching for Lincoln's motivation to get into politics in the first place for a reading lesson.  

"I can not but hate [the declared indifference for slavery's spread]. I hate it because of the monstrous injustice of slavery itself. I hate it because it deprives our republican example of its just influence in the world -- enables the enemies of free institutions, with plausibility, to taunt us as hypocrites -- causes the real friends of freedom to doubt our sincerity, and especially because it forces so many really good men amongst ourselves into an open war with the very fundamental principles of civil liberty -- criticising [sic] the Declaration of Independence, and insisting that there is no right principle of action but self-interest.

Before proceeding, let me say I think I have no prejudice against the Southern people. They are just what we would be in their situation. If slavery did not now exist amongst them, they would not introduce it. If it did now exist amongst us, we should not instantly give it up. This I believe of the masses north and south. Doubtless there are individuals, on both sides, who would not hold slaves under any circumstances; and others who would gladly introduce slavery anew, if it were out of existence. We know that some southern men do free their slaves, go north, and become tip-top abolitionists; while some northern ones go south, and become most cruel slave-masters.

When southern people tell us they are no more responsible for the origin of slavery, than we; I acknowledge the fact. When it is said that the institution exists; and that it is very difficult to get rid of it, in any satisfactory way, I can understand and appreciate the saying. I surely will not blame them for not doing what I should not know how to do myself. If all earthly power were given me, I should not know what to do, as to the existing institution. My first impulse would be to free all the slaves, and send them to Liberia, -- to their own native land. But a moment's reflection would convince me, that whatever of high hope, (as I think there is) there may be in this, in the long run, its sudden execution is impossible. If they were all landed there in a day, they would all perish in the next ten days; and there are not surplus shipping and surplus money enough in the world to carry them there in many times ten days. What then? Free them all, and keep them among us as underlings? Is it quite certain that this betters their condition? I think I would not hold one in slavery, at any rate; yet the point is not clear enough for me to denounce people upon. What next? Free them, and make them politically and socially, our equals? My own feelings will not admit of this; and if mine would, we well know that those of the great mass of white people will not." 

-Abraham Lincoln, October 16, 1854: Speech at Peoria, Illinois

Reconfirming why I am an elementary school teacher and not a politician. But, wow, the irony that a man with conflicting ideals could have such a radical effect on the country and slavery itself... it really boggles my black-and-white thinking mind.