My impression is that polemic has been a lot more raw in other times and places.

This is true (American political discourse has been astonishingly crude in in the past).

But was it more effective? That is the issue. To use a Revolutionary War example, it was not one of the crude blood-libelous circulars that sold 500,000 copies, but Paine's Common Sense.*

* It struck me as pretty well argued and reasoned when I read it in middle school, but that was a long time ago.