A political hack is a negative term ascribed to a person who is part of the political party apparatus, but whose intentions are more aligned with victory than personal conviction. The term "hired gun" is often used in tandem to further describe the moral bankruptcy

Moral bankruptcy

Moral bankruptcy is a synonym for immorality that has gained popular usage in the fields of business and politics, in which it specifically implies some instance of political corruption or corporate crime...

of the "hack".

Political hack may also be used by a political opponent in order to erode confidence or credentials of an opponent or his hired campaign help. Often used to demean well credentialed individuals for political purposes.