"Representatives and direct Taxes shall be apportioned among the several States which may be included within this Union, according to their respective Numbers, which shall be determined by adding to the whole Number of free Persons, including those bound to Service for a Term of Years, and excluding Indians not taxed, three fifths of all other Persons"
There is a great deal of misunderstanding about how this clause ended up in the Constitution. It was initially the Northern position that slaves should not be counted at all. It was the Southerners who wanted slaves counted. Why? Well, what good did representation in Congress or anywhere else do to a person with no rights? In fact, all that would be accomplished by counting slaves would be to give slave owners more representation in Congress; and the more slaves they owned, the more power they would have.
So naturally, the Southerners held up the Northerners, refusing to sign on to the Constitution (which their descendants now claim to hold so sacred) until this "compromise" was worked out. Once again, the more progressive elements of the country, including the Republicans' cherished founding fathers, were blackmailed into giving the racist reactionaries a victory, in order to achieve what was seen as a greater good.
I don't mention this now to point out the malignant hypocrisy in everything the Republicans do; that is obvious to everyone. At the moment, I am more interested in the fact that, from the beginning of this country down to today, this has been standard operating procedure for Conservatives in America: holding the country hostage and demanding huge payoffs before they will even consider doing the right thing, even when it is as simple and as clear as providing medical benefits for 9-11 responders, or (my God) freeing their slaves.