Sure there might be some implicit attacks on other groups, but for the most part they are left unsaid. Lewis' corporate welfare bums rallying cry was about the only time in my memory that the NDP went negative in that way and while it returned a highwater mark of seats, given the times (and I was there) they should have been able to do much better and it was not very long after that Lewis lost his own seat and the NDP was greatly reduced in parliament in (was it) 75 (I forget), so there was no long term gain out of that negative campaigning. (Or it turns out sucking up to the Liberals Mr. Dobbin)
Wasn't that about the time that what is now the Canadian Council of Chief Executives formed? As I understand that history, the goal was to remove the NDP from having the balance of power so that the Liberals could do Bay Street's bidding without interruption. That was followed by wage and price controls, and we all know how well that ended for the Liberals in 1979.