Who runs the world? Philosophers! Not really, but Hythloday thinks they should—and they kind of do in Utopia. In fact, Hythloday thinks that the political health of Europe is in serious danger if kings without any philosophical know-how continue to run the show. In fact, the question of how to make the ideals of philosophy reconcilable with the realities of politics motivates the long debate of Book 1 of Utopia and is a subtle refrain in Hythloday's depiction of the island. For all their innovative and radical attitudes toward society, power, and religion, it's their devotion to learning and education that keeps the Utopians so on top of things.
Hythloday's point is that politics and philosophy are naturally connected; there's no way you can possibly separate them.
Philosophy can never be political; it has to be able to conceive of an ideal world and never engage in the kind of compromises politics requires.