Literally no, or rather I should say, if only that were the case!!

The literal definition of the word moron is a mental age between 8-12, or in terms of IQ score between 51-70.

Whereas propaganda can affect people with literal PhDs, trained in the craft of problem-solving and discernment of the true hidden behind many sometimes conflicting facts.

Of course, I am aware that you meant the term more in the colloquial sense of "foolish or notably stupid person". But therein lies the danger due to such ambiguity.

We should think of propaganda less dismissively imho, as in not something that mere morons would fall for, and rather as something that you or I and everyone we know or even do not know could easily fall for as well.

Propaganda affects not merely morons (implication: we here are safe) but PEOPLE.