The Pope made sweeping changes in the Catholic Church, including many of the things that anti-Catholics hated most about it, and perhaps most importantly (especially in the preception of non-Catholics like myself), his work in secular matters. He helped to smash Communism--not only through Solidarity in Poland, but all over the world, and thus bring down an empire that made the Nazis look like pikers.
But wait...I thought Reagan brought down communism all by himself?