The main purpose of the Graham Hoffman Act is to enhance the legal protections for first responders, such as firefighters and law enforcement officers, by establishing stricter penalties for crimes committed against them while they are performing their official duties. The act aims to deter violence against these critical public servants and ensure that those who harm them face significant consequences. Key provisions of the act include the establishment of a new federal crime for knowingly assaulting a first responder, which can result in up to 10 years of imprisonment.