Final answer:
Alexis de Tocqueville believed that American democracy was an unstoppable force that would overthrow monarchies around the world, as stated in his book Democracy in America.
Step-by-step explanation:
Alexis de Tocqueville believed that American democracy was an unstoppable force that would one day overthrow monarchies around the world. This can be seen in his two-part work entitled Democracy in America, published in 1835 and 1840. In his analysis of the democratic revolution in the United States, Tocqueville highlighted the benefits of democracy such as equality before the law, but also warned of the negative consequences, including the potential for tyranny of the majority.