Yet to elect Abraham Lincoln, the right of suffrage was extended to free negroes in Vermont, Massachusetts, Ohio, New York and other Northern States, although the Supreme Court has declared them not to be citizens of this nation. Yes! Our slaves are first stolen from our midst on underground Railroads, and then voted at Northern ballot-boxes to select rulers for you and me. The memory of our fathers is slandered when this is declared to be according to the Constitution. –Thomas R. R. Cobb,
Address to the Georgia legislature,
November 12, 1860

Which idea does Cobb use to support his argument?

Votes cast by free African Americans in the South should not be counted.
The election was unfair because it counted votes cast by African Americans.
The Constitution says that free African Americans are citizens.
The election was unfair because Lincoln was not on the ballot in the South.