To best explain the legislative process, a flowchart showing the passage of the bill in both houses and then moving on for the president’s approval would be the most effective visual aid.
A flowchart allows you to depict the sequential steps involved in the legislative process clearly, from the introduction of a bill, through various stages in both the House of Representatives and the Senate, and finally to the president's decision. This format provides a clear visual representation of the process and helps to illustrate the flow of actions, making it easier for individuals to understand how a bill becomes law.