The main purpose of this legislation is to strengthen immigration laws by expanding the definition of "aggravated felony" to include serious drunk driving offenses. The goal is to enhance public safety by ensuring that individuals convicted of severe drunk driving incidents face stricter immigration consequences. Key provisions of the law include the addition of a new category of aggravated felony that encompasses offenses related to driving under the influence of alcohol or drugs, specifically when such actions result in the death or serious injury of another person.