According to the American people, torture is justified, and it works.
Every demographic has at least a plurality for torture: men and women, young and old, white and non-white.
The only good finding is that a plurality of Democrats believe torture was not justified, though, within the margin of error, they do believe it was helpful.
Before Bush, most Americans were against torture. The endless drumbeat of propaganda and the need to justify what America does (America is good, therefore America does not do evil), has had its effect.
I will make an ethical judgment: people think torture is justified are bad people. Depraved people. A society where a majority thinks it is justified is a depraved culture. (And remember, 51% think it was justified, but 20% don’t have an opinion. Only about a third of Americans are opposed.)