Although the Jedis did assist the Rebel Alliance in overthrowing a tyrannical emperor, it's clear that the Knights were originally setup to enforce the Galactic Senate's big government agenda.
I must say, I find Jesse's lack of faith disturbing. Based on the Star Wars films, we know very little about the Galactic Senate's pre-Phantom Menace agenda, but we do know that Chancellor Valorum is a pretty weak leader. We also know Palpatine's designs. Upon becoming chancellor, he vows to put down the separatists, raises a Grand Army of the Republic, stays in power well beyond the expected number of years/terms, and finally reorganizes the Republic into the First Galactic Empire. That's as big of a big government agenda as you're going to get.
Are the Jedi big government advocates? That's unclear. I think it would be more accurate to describe them as cartelistic -- they refuse to permit a free market in learning the ways of the Force. After all, the Jedi Council's initial inclination is not to train Anakin Skywalker despite his obvious talents, using some BS about fear as a cover. Only when Qui-Gon threatens to go rogue do they relent. The Council does not inform the Senate that their ability to detect the force has been compromised. They're reluctant to expand their assigned tasks -- they're keepers of the peace, not soldiers. Just as clearly, their anti-competitive policies weakened their own productivity, given the fact that they were unable to detect a Sith Lord walking around right under their noses for over a decade.
So, were the Jedi perfect agents of liberty? No, probably not. But neither were they handmaidens to the greatest concentration of state power in galactic history.
P.S. Beyond George Lucas' rather bigoted portrayal of anything involving commerce, another source of libertarian resentment against the Jedi might be their lack of respect for property rights. If the Force is an energy field created by all living things, then why the hell to the Jedi get to exploit it without compensating the creatures who create it in the first place? If you think about the Jedi as the Guardians of the Republic, this might sound absurd. Replace "Guardians of the Republic" with "rapacious strip-miners of primordial energy," however, and suddenly they don't look so good. At least the Sith stay small in number, so the externality problem is kept to a minimum.
Daniel W. Drezner is professor of international politics at the Fletcher School of Law and Diplomacy at Tufts University.