Rephrase a statement expressing surprise that some people don't understand SBlarney's reference to the term "useful idiot" regarding Trudeau, despite the fact that it is a commonly known expression.
PARAPHRASING. I can't believe how people cannot understand what SBlarney was doing. We know Trudeau didn't actually call anyone an idiot, but there is an expression "useful idiot", (like Trump is referred to by Russians) and that would be what SBlarney was referring to.