More and more, I wonder whether Leo XII should not have been so tolerant of democracy. Perhaps it ought to be condemned alongside communism as well. Certainly its foundational principle that authority emanates not from God, but from the will of the people, is antithetical to the Kingship of Christ.
I don't think he was completely tolerant of democracy. He wrote the encyclical Rerum Novarum (on the rights and duties of capital and labor) in 1891. It was then used as a basis for Chester-Belloc's Distributist views.
Link:
Rerum Novarum (May 15, 1891) | LEO XIII (vatican.va)The above link appears to not be working. The encyclical can be accessed from the bottom of this Wiki page:
Rerum novarum - Wikipedia