The parties themselves - for the most part, no. A party, it seems to me, represents a set of values focused on a particular ideal. And by 'ideal', I mean both definitions: the principle and the utopia/"perfect" situation.
I think "extremists" - those on either far end of the conservative/liberal continuum who might even be so militant as to have a "by any means necessary" or "the ends justify the means" attitude, and view the "other" through a moral lense, can be very corrupt.
Politicians who are focused on "their" party, and/or especially those whose main priorities have to do with reputation and political career advancement - who truly see the world as functioning by "appearance" as much as or even more than truth - and who act accordingly - yeah, they're corrupt as hell.
As is the system, inasmuch as it has become one that is teetering toward self-preservation rather than serving the needs of the society that created it.