Of all the arguments against voluntary euthanasia, the most influential is the 'slippery slope': once we allow doctors to kill patients, we will not be able to limit the killing to those who want to die.
In the past, I often found that when I reached out for a fast cure it led me down a slippery slope of more medications, hopeful dependence on the next prescription and ultimately a much longer drawn-out illness.
Torture is such a slippery slope; as soon as you allow a society or any legal system to do that, almost instantly you get a situation where people are being tortured for very trivial reasons.
There is no 'slippery slope' toward loss of liberties, only a long staircase where each step downward must first be tolerated by the American people and their leaders.
Never bend the rules. You bend the rules a little bit and then it's a slippery slope.