Which piece of textual evidence best supports the writer's idea that "statesmanship is not an abstract skill, but a contextual one"?

Adapted from "Lincoln the Great" by Wilfred W. McClay

"Lincoln rose to prominence as a politician who was antislavery but also a gradual emancipationist. The strategy he preferred would have contained the spread of slavery, then gradually eliminated it—as opposed to overturning the institution in one grand gesture."

"Lincoln's strategy failed in the end, since the South concluded that it could not trust President Lincoln, who received not a single electoral vote from the South, to protect its 'peculiar institution.' But it was a position predicated on Lincoln's belief that the maintenance of the Union was paramount above all other political goods."

"It is harder to swallow Lincoln's frank disbelief in racial equality and his support for African colonization schemes. But what should count for us is the fact that, in the maelstrom of war, Lincoln overcame his disinclinations to see that the Union could only be preserved if it sought to achieve something greater than its own survival."

"Statesmanship is not an abstract skill, but a contextual one, highly specific to the circumstances it finds. It is irresistible to wonder what kind of leader Lincoln would have been had he faced different circumstances."