https://www.marxists.org/reference/archive/mao/selected-works/volume-4/mswv4_65.htm
As the other poster says, define democracy.
Exploring Communist, read: statist, notions of what democracy is as well as what Western notions of democracy is, especially in the context of multiculturalism is at least an interesting angle.
The United States is democratic by its own definition, and China isn't democratic by American definitions. China is democratic by its own definition, and the United States isn't democratic by Chinese definitions (look up bourgeois democracy).
This is a more interesting angle than simply arguing that China is a democracy by Western definitions, and if you have time, you can also consider Iran.