You misread it. It's only about slavery.
Here is the key statement:
"On the 4th day of March next, this party [abolitionist Republicans] will take possession of the Government.That is their key reason, and it is false.
It has announced that the South shall be excluded from the common territory, that the judicial tribunals shall be made sectional, and that a war must be waged against slavery until it shall cease throughout the United States."
I can’t fight dumb.