What is Horace Greeley's prediction for Lincoln's efforts to "put down the rebellion, and at the same time uphold its inciting cause"?

Greeley could not believe that Lincoln could have a balance in saving the Union without freeing the slaves, since he (Lincoln) could be inflamed by the slaves of the border states. All efforts to end the rebellion would not be worth it.

This ended up occurring, because Lincoln has not yet been able to resolve the issue of slavery.

Explanation: Greeley's predictions posted in articles in the New York Tribune newspaper, and of which he was its editor, before the Civil War, were useful for adding more fuel to the fire, and for strongly criticizing President Abraham Lincoln, especially in matters concerning the slavery that kept the states of the North and the South divided. And considering that the South had to separate, position considered controversial in the midst of secession crisis.