Meina Gladstone is the Hegemony CEO. That's kind of like the president, except of the whole honking universe. People of the future seem to treat government like a business, with a CEO instead of a president or king.
Wait, this is set in the future?
We first meet Meina Gladstone Princess Leia-style: a hologram asking for help. It seems like it might even be her idea to send the seven chosen pilgrims to Hyperion. The Consul says, "the press loved to compare [her] to Lincoln or Churchill [...] or whatever other [...] legend was in historical vogue at the time" (Prologue.17).
First: teehee, because these famous leaders are not considered legends. Second: she obviously knows her business: "[Brawne Lamia's dad] had once described Meina Gladstone as the only political genius in the Hegemony" (5.966).
The thing is, she might just be an evil genius. She's been pulling the strings for years since she was just a Hegemony Senator: she orchestrated the Ouster assault on Bressia. She sent the Consul on his mission to provoke the Ousters into attack, putting millions of lives at stake for her own (unknown) personal goals. Not to mention however she might have coerced each pilgrim into agreeing to this.
Just exactly who isn't being played by Meina Gladstone?
Meina Gladstone's actions don't reflect well on the government as a whole. With her as its main figure, she represents a government at its most evil and corrupt. She's not just waging war under false pretenses or forcing the country into socialism: she might just be destroying humanity itself.