That's not always easy.
I've hinted at some potential calling cards in a comment elsewhere: "...keeping people from voting, or forcing them to vote for a particular candidate, or prohibiting certain political parties..." But that's just a start.
For example, Amnesty International would include harassing or arresting dissidents.
Wikipedia's entry interprets its sister phrase ("political repression") broadly:
Political repression may be represented by discriminatory policies, surveillance abuse, police brutality, imprisonment, involunatry [sic] settlement, stripping of citizen's rights, and violent action such as the murder, summary executions, torture, forced disappearance and other extrajudicial punishment of political activists, dissidents, or general population.Clearly, the affirmative is at an advantage with a broader definition, allied with a proportional or tit-for-tat definition of justice.
The Neg, then, could argue for the importance of the word "political," which implies a political purpose or focus of action, precluding actions against the "general population," which could include genocide and shift the debate too far toward the Aff. The resolution doesn't cover mere "oppression" (as it did the last time this topic was in play). A too-broad definition makes "political" meaningless.