They are right in the sense that truth is easy to convey to an audience and that simple minded people will easily be persuaded by true statements.

It requires a rather average/high IQ to be convinced by/understand leftist mental gymnastics. This is also where the leftist midwit NPC meme came from.

They're wrong in the sense that ignorant and immature people often fall for leftist slogans that don't require any brain cells, like Black Lives Matter and the like. Statements that most people agree with when they hear them and that they then use for political agendas.

Leftists are liars, hypocrites and pretenders.