When members visit a community, they copy what they see other members doing. The important word in that sentence isn't 'doing', it's 'see'. You get to decide what members are likely to see. Your moderation strategies shapes what members see and, thus, what members do.
Moderation isn't removing the bad stuff, it's making clear decisions about what you want members to be doing, and emphasizing those elements.
If you want members to discuss fiscal policy, then highlight those discussions, interview members discussing that, create a poll about fiscal policy, make fiscal policy discussions sticky threads.
Your moderation strategy shapes your community. It nudges members to take the actions you want. Pro-actively establish your strategy. Don't reactively remove the bad stuff.