Liberals love slavery. Their only real objection to the pre-1865 chattel slavery in America is that the slaves were privately owned.
But it's obvious that they have no problem with the idea that the government owns the people, and can dispose of their lives, liberty and property in any way it sees fit as long as it is done in the name of the public good (i.e. the "General Welfare").
At least that's what it says in the so-called "Living Document" version of the Constitution, which in these more enlightened times is now seen to mean the exact opposite of what it actually says.