Logged into your Facebook account on a desktop, head to this page. Here, you'll see all of your so-called "ad preferences," divided up by interest category like News and Entertainment, Business and Industry, People, etc. These include both specific pages you've liked and broader categories of things Facebook thinks you're into based on every click, scroll, and hover you've made in your Newsfeed.
Click on the Lifestyle and Culture tab, and look for the box labeled US Politics (you may need to click "More" if it doesn't show up on the first page). Are you the Very Liberal, Moderate, or Conservative it's ascribed you to be? Even if you've never liked a particular candidate's page, or even a politically charged post of any sort, Facebook tries to predict your personal feelings by gauging the self-professed political identities of people who like the same pages that you do, and lumping you in with them.