I disagree with the statement. I don't think enforcement of political correctness would have had any impact because his words hardly mattered to begin with. Events were everything. If it wasn't Hitler it'd probably have been someone else, and that someone probably would have some famous quotes to their name. His words boil down to:

1. Patriotism. Germany is great, Germans are great.

2. Socialism (calling each other comrades, talking about how awesome the working class/"labour" is, calling for an end to class differences).

3. Generic vibes. The Nazi party is great, the future is bright, we are powerful, etc.

... expressed in a muddled and often incoherent way. (and in his book, hatred of the jews, but that doesn't get featured in their propaganda films).

The only obvious thing in the Triumph of the Will excerpts that would be red flags by today's standards are the open and explicit glorification of dictatorship. And for some people the socialism, but in the 1930s people didn't know what we know now about how that works out.

Now come up with a speech code that can forbid those things yet not also ban either of the two main American political parties.

> The most fundamental part of my position is that I find it hard to believe that the average german citizen, in a calm and rational state of mind, would have decided World War 2 was in their individual self-interest.

Hitler didn't literally say in his speeches "Let's start another world war", did he? And by the time he got into power and did start it, it was too late, speeches didn't matter anymore.

But let's put that to one side. Remember that in Germany in the 1920s and 30s democracy was brand new and very weak. From the perspective of people who had been used to monarchy it was absolute bedlam. Political parties were engaging in open street warfare, the government was run by fragile coalitions made up of lots of tiny parties that constantly bickered and collapsed, there was hyperinflation and then France and Belgium actually invaded Germany to seize the factories when it proved unable to pay the war reparations. Then things recovered briefly before the Depression hit. The constitution meanwhile allowed the president to suspend the whole democratic process and rule as a dictator in an "emergency" which wasn't defined. Hitler used this, but he wasn't the first, Hindenburg used it before him so normalizing the procedure. It was absolutely nothing like today's relatively rich and stable western democracies. Times were desperate.

So for the average working class German this whole experiment with democracy would have looked SNAFU. The economy was hosed, Germany was being oppressed by the victors of WW1, they feel like shit because they lost, the government wasn't working and there's no national pride anywhere (something very important to most workers who aren't very mobile at this time), and the democratic process was barely working. In steps a guy who very clearly (a) has a lot of energy, (b) promises to fix everything if given the power to just get rid of this stupid voting system and (c) is a patriot and socialist. He may not be articulate but so what, fancy men with fancy words had plenty of chances but haven't fixed anything. If you don't believe much in democracy to begin with because your experience of it has been bad, why wouldn't you elect a strongman who says the right things? That's how you'd pick your politicians anyway. They didn't know he'd start a world war and then lose it.