When Teddy Roosevelt called the presidency a bully pulpit, he was not talking about bullying. He meant it was a terrific place to preach from.
In Roosevelt's day, bully was a slang adjective meaning superb, first-rate, wonderful. To say bully was to say great. So a bully pulpit was a magnificent platform, the best possible stage from which to be heard.
Roosevelt's insight was that the presidency was exactly that kind of stage. The office gave him a voice louder than anyone else's in the country, and a press that hung on his every word. He could set the national agenda not just by signing laws but by talking, by using the office itself to move public opinion.
The phrase captured something new about modern leadership. Power was no longer only about formal authority. It was about attention, about the ability to command the conversation and rally the public to push the government where you wanted it to go.