To be honest, yes, this is very true. Politicans use this all the time... and I just hate it when they talk for like 30 minutes and basically say nothing.
Business people too. They have a way of speaking that kind of pacifies and exhausts you, so that by the time they're finished speaking you're confused and don't really feel like arguing anymore
There is an ancient 1400 year-old Arabic saying that goes إن من البيان لسحرا "in eloquence there is magic" or "some eloquence is magical". It is an ancient tactic.