These two things don't rule out each other.

Quite to the contrary, when we observe rampant cheating from the presidency down to shrinkflating food and freeriding the subway, it is a good argument for having an universal morality problem.

There isn't a dichotomy between the saintly people and the scummy political class. A nontrivial part of the voter base of the scummy politicians is formed by regular scummy voters.