But if it is a wrong, he cannot say people have a right to do wrong. He says that upon the score of equality, slaves should be allowed to go in a new Territory, like other property. This is strictly logical if there is no difference between it and other property. If it and other property are equal, his argument is entirely logical. But if you insist that one is wrong and the other right, there is no use to institute a comparison between right and wrong. You may turn over everything in the Democratic policy from beginning to end, whether in the shape it takes on the statute book, in the shape it takes in the Dred Scott decision, in the shape it takes in conversation, or the shape it takes in short maxim-like arguments,—it everywhere carefully excludes the idea that there is anything wrong in it.
That is the real issue. That is the issue that will continue in this country when these poor tongues of Judge Douglas and myself shall be silent. It is the eternal struggle between these two principles—right and wrong—throughout the world. They are the two principles that have stood face to face from the beginning of time, and will ever continue to struggle. The one is the common right of humanity, and the other the divine right of kings. It is the same principle in whatever shape it develops itself. It is the same spirit that says, “You work and toil and earn bread, and I’ll eat it.” No matter in what shape it comes, whether from the mouth of a king who seeks to bestride the people of his own nation and live by the fruit of their labor, or from one race of men as an apology for enslaving another race, it is the same tyrannical principle. Page 431
https://www.bartleby.com/251/pages/page431.html
Slavery is founded in the selfishness of man's nature -- opposition to it is in his love of justice. These principles are an eternal antagonism; and when brought into collision so fiercely, as slavery extension brings them, shocks, and throes, and convulsions must ceaselessly follow. Repeal the Missouri Compromise -- repeal all compromises -- repeal the declaration of independence -- repeal all past history, you still can not repeal human nature. It still will be the abundance of man's heart, that slavery extension is wrong; and out of the abundance of his heart, his mouth will continue to speak.
--October 16, 1854 Speech at Peoria
The Autocrat of all the Russias will resign his crown, and proclaim his subjects free republicans sooner than will our American masters voluntarily give up their slaves. --August 15, 1855 Letter to George Robertson -
http://www.abrahamlincolnonline.org/lincoln/speeches/robert.htm
You know I dislike slavery; and you fully admit the abstract wrong of it.
--August 24, 1855 Letter to Joshua Speed - -
http://www.abrahamlincolnonline.org/lincoln/speeches/speed.htm
The slave-breeders and slave-traders, are a small, odious and detested class, among you; and yet in politics, they dictate the course of all of you, and are as completely your masters, as you are the master of your own negroes. --August 24, 1855 Letter to Joshua Speed =
http://www.abrahamlincolnonline.org/lincoln/speeches/speed.htm
Using this quote, and the others you cite, a case can be made that Lincoln had in his heart the desire to overthrow the pro-slavery provisions of the United States Constitution.
As an educated man, he must have known he could not get the votes to over-throw the pro-slavery U.S. Constitution peacefully.
What Lincoln would need was a pretext.