I do not for one moment believe that the Americanism of today should be a mere submission to the American ideals of the period of the Declaration of Independence . . . Such action would be not only to stand still, but to go back. American democracy, of course, must mean an opportunity for everyone to contribute his own ideas to the working out of the future. But I will go further than you have done. I have actively fought in favor of grafting on our social life, no less than our industrial life, many of the German ideals.
There is a lot here. First, we see the exact same disdain for the Declaration via the ideals that made it so great. But beyond that, Roosevelt states plainly that he is promoting Germanic ideals(Prussianism), which is something that I have made observations about in the past. You can trace a lot of progressive roots back to Germany, idea wise. But most importantly, note how he uses the phrase "to go back". That is the exact kind of arrogance that progressives have held for well over a century now, that these ideals that made America so great are somehow 'backward', or regressive. Liberty is not backward. The tyranny of progressivism is what's backward.
Every progressive means harm to the USA, democrat or republican - all progressives. All of them. That is their intent. And after a century of these people and their ideas and policies, it's inarguable. They have proven it in their actions and words.