I believe Socrates and/or Plato believed that Greece should be led by a "philosopher king."
I argue that Plato believed democratic governance to be erratic and
dysfunctional and that the democratic ruler is led by unnecessary
appetites and passions.
Plato and Machiavelli on Democracy
Jean Paul-Sartre was a huge fan of Che Guevara and the Cuban revolution, which, according to one's perspective, can be regarded as the antithesis of democracy or one of the greatest democratic coups in modern history.
His [Sartre's] preference for mass movements and bottom-up social
organization suggest that he would favor radical participatory
Sartre's Political Philosophy
These are just a couple examples to get you started.
Of course, philosophy is a huge part of political "science," so you should take a look at Karl Marx and other political thinkers.
I've often heard democracy disparaged as "mob rule." I think this is largely a right-wing attitude, though I'm not certain.
However, as a political activist, I've come to largely agree. In particular, I'm struck by the fact that some of history's most inspirational leaders were dictators.
Which isn't to say democracy is a lost cause; it's just a very difficult thing to create and sustain. If a chain is only as strong as its weakest link, then a democracy is limited by the intelligence and selflessness of its citizens.
Also, note that governments typically become more authoritarian in response to perceived threats (typically war) and as corrupt elements take control of governments.
It has been observed that a pure democracy, if it were practicable,
would be the most perfect government. Experience has proved that no
position is more false than this. The ancient democracies, in which
the people themselves deliberated, never possessed one good feature of
government. Their very character was tyranny; their figure deformity. -- Alexander Hamilton