I think we all believe that there are rights that should Never Ever be done away with, no matter what the cost. And if the government asked to violate it, that's a sign that they are inherently being untrustworthy. Suppose that a government said that it was necessary to knowingly inflict a cruel and unusual punishment in a particularly egregious circumstance. I think you'd agree that it is insufficient to let the government do this, and let the courts sort it out in a few years, well after the fact.