If you were a white Colonial landowner in the South, why would you want the slave population to be counted for the number of representatives assigned for your state in the proposed federal government?
If you were a man who had just fought in the War against the British government arguing that you had inalienable natural rights which the King or Parliament had abused, why might you be uncomfortable referring to the fact that some people in your society still legally owned other people (as slaves)?
If you were a white woman living anywhere at this time, what might you have said about these ideas?