The foundation stone of national life is, and ever must be, the high individual character of the average citizen. (96) 

Just like Captain Planet, TR ends his speech with saying, "The power is yours!" 

The character of the average citizen is paramount in Teddy's view of the world, and he wants to stack the deck with the right kind of people in the upper and lower classes alike. The emphasis has been placed on individual actions throughout the speech, and here he just wants to hammer that point home.