Superheroes are democratic ideals.
They exist to express what's noblest about us: selflessness, sacrifice, a commitment to protect those who need protection, and to empower the powerless.
Superheroes are fascist ideals.
They exist to symbolize the notion that might equals right, that a select few should dictate the fate of the world, and that the status quo is to be protected at all costs.
Both of these things are true, and inextricably bound up with one another — but they weren't always.