Never touched Political niches, but I would imagine in the current climate controversy and polarising political views would do quite well for clicks. Stuff that feeds into the outrage culture to generate debate, sharing and opinion.
If you have a blog for the niche, the biggest benefit would be your images to get views as on sites like Facebook people click more for the image than the actual subject matter of the post. So applying this to Pinterest would be easy, start by having the posts include have some kind of primary pillar image that is high res, well made and easily tells the user what they are likely to be reading out i.e if its a post about Trump doing something outrageous, have some picture of him looking crazy, angry or pointing the finger. As images like this self affirm peoples beliefs against any given person. Then its just a matter of including a caption on the image about the subject matter, and rolling on with the content that is highly shareable.
Next stop, join big group boards and start getting your pinned images to the masses.