Actually Triumph of the Will is from the 1934 Nazi Party Annual Rally. Interestingly, the copyright is owned by the German state and hence here in Germany you can only see it as part of an educational screening in museums or such. It will always include commentary and an introduction.
while the rhetoric in this film might be especially obvious, there are enough other examples for it. And for someone like me who grew up learning that we have a responsibility that this part of my country's history May never again repeat itself, a lot of political rhetoric easily becomes cringe-worthy, especially listening to US politicians. But I don't think it is the rhetoric that make something bad, it is the content. While certain means might be a warning sign (if I sell by appealing only to feelings, not to ratio) it is no way a sign that everything is bad.
Sorry for the thread thrift, it is just a topic that makes me write a lot (and if you make the connection of marketing a product instead of ideas in a purely emotional, not rational form, we could even make a connection back to those who sell pixie dust ;-) )