Jacobs said two books about intensely powerful men is probably enough for the time being. People couldn't stand up to him. Burton was a champion of the dispossessed and the under-represented. He was their advocate. He didn't take money from anyone and died very nearly broke.
Most politicians are satisfied with making the big speech and grabbing the headline.
They don't care if their issue loses. Burton, however, skipped the speeches and the headlines and his issues didn't lose because he worked harder and longer than anyone else. You might say that, politically, Burton gave obsession a good name.