Who said slavery has been done away with? The Emancipation Proclamation didn't get rid of the plantation; it expanded the plantation, thanks to the federal government. Now Americans have to ask the government for permission to do everything, from cutting down a tree in their own yard to starting a business with their own money.
The states are enslaved to the federal government, too. They can't even secede without an administration threatening to send in "taskmasters" to stop them. States no longer elect their own representatives (Senate), but now they must relegate that duty to the federal masters.
Those Senators are apologizing for an institution which has led to the very chains they wear today in the seats of Congress, locked up by arbitrary powers from the executive branch. Just because the whips are gone doesn't mean our Senators aren't picking cotton for the global elite to enslave the masses by over-regulation, over-taxation, over-spending, and over-stepping of constitutional boundaries.
They make me sick right now, brown-nosing on a guilt trip towards those who perpetuate the same atrocities which they blame others for without reason.