As the leader of the Republican Party during the debates of 1858, Abraham Lincoln was a strong opponent of the expansion of slavery into the territories of the United States. He believed that while he did not advocate for the immediate abolition of slavery where it already existed, it was morally wrong and should not be allowed to spread further.
Given this context, the statement that would best fit with Lincoln's position would likely emphasize the belief that slavery is a moral wrong, the importance of limiting its expansion, and the principles of equality and liberty as foundational to the nation.
For example, a statement like "Slavery is a moral, social, and political wrong, and it should not be extended into new territories or states," would align with Lincoln's viewpoints during that period.