Final answer:
The president has a strong impact on policy through their role in the legislative process, influencing public opinion, and using institutional powers and informal powers of persuasion and negotiation.
Step-by-step explanation:
The president has a strong impact on policy because they interpret legislation. The president's role in the legislative process is crucial in setting the policy agenda and crafting legislation.
While the president cannot introduce bills in Congress, they can influence public opinion, use the media, and engage in public messages to shape legislation.
Additionally, the president holds direct institutional powers and informal powers of persuasion and negotiation essential to working with the legislative branch.