Morally speaking, the majority sinks to the level permitted by the government. If the government says, "Well, we have this coliseum so what are we going to do? We're going to have people kill one another and sell tickets. And instead of using lanterns we'll light slaves and we'll burn them to death as our lanterns."
Now what do the people do when the government sinks to that level? They buy tickets. They go. The Coliseum is standing room only. It's like a major NFL stadium of today only it was in Rome 2000 years ago. And in all the major cities of the Roman empire they built their little coliseums and Roman theaters and they just were thrilled watching human beings slaughter one another in torture and pain.
The majority sinks to the level permitted by government. If the majority IS the government, then what will stop a nation's decline?