...rigid and inflexible, determined by those few who know best
...flexible, always changing with the changes in popular opinion
...somewhere in between #1 & #2
Other (please elaborate)
If, when defending your support for Donald Trump, and your response is,
"But but but... HILLARY!!!", then you lost the argument before you even began.
A long time ago, it was more acceptable for people to litter the streets. Now, if you throw a can on the street, you are looked at with disgust by other people and rightfully so.
This is an example of how morals changed. Who changed them? Society, on all levels worked to change this. From a vocal minority to the public consciousness the anti-street litter movement impacted more and more people switching our perception of right behavior and etiquette.