Overall morale is declining. Call it the Trump Effect. Having a leader who behaves like he did normalizes this behavior and immoral behavior becomes more commonplace since people feel its legitimized.

I'm far from being a liberal but that guy objectively didn't show manners, so why should the man on the street..

My theory, for which I have no evidence beyond subjective observations, is that Trump jumped on a burgeoning trend (that behavior was trendy before Trump's election, and similar patterns predate him in other countries) and pushed the country over the edge. Many people I know who despise Trump seem to follow his lead in their behavior.