All pending legislation should be required to have a topic sentence. Every tenet of the bill must address some aspect of that topic sentence.
Bills are currently frequently written and rewritten with non-related riders. This practice dramatically slows the legislative process by introducing multiple, occasionally contradictory proposals that must be discussed before voting can take place. Requiring a topic sentence would also dramatically reduce the amount of 'pork' that is currently seen in bills.
Requiring that all proposed legislation address a single topic would streamline the process of lawmaking and eliminate one way in which 'politics' hinders the legislative process.