Did Abraham Lincoln believe in white supremacy?

The idea of Abraham Lincoln’s endorsement of white supremacy stems primarily from his pre–Civil War position. While running for US Senator from Illinois in 1858, during the Charleston debate with Stephen Douglas, Lincoln denied being an abolitionist and spoke these words:

There is a physical difference between the white and black races which I believe will for ever forbid the two races living together on terms of social and political equality. And inasmuch as they cannot so live, while they do remain together there must be a position of superior and inferior, and I as much as any other man am in favor of having the superior position assigned to the white race . . .

Subsequent analysis of this speech has cast it as a political position that Lincoln did not fully endorse, and it has claimed that he was referring to skin color alone, rather than capabilities. In later positions, Lincoln would express the idea that black people were entitled to the rights of all Americans according to the Declaration of Independence. Locating Lincoln’s views within the widespread racial prejudice of the day, many argue that he was a moderate.
The question of his white supremacy feeds into a related characterization of Lincoln as a reluctant emancipator rather than the Great Emancipator. These debates consider his motivations in issuing the Emancipation Proclamation in 1863 and its relationship to the Thirteenth Amendment, which was ratified in 1865.