Cory Booker promised to overhaul the U.S. immigration system and all but end the detention of illegal immigrants in a new 2020 campaign proposal.

The New Jersey senator and Democratic presidential candidate released his proposal for reforming the U.S. immigration system on Tuesday. The proposal would stop federal law enforcement officers from detaining illegal immigrants in most cases unless the migrant threatened public safety, according to the plan.

Booker promised to end private prisons, about 65% of U.S. detainment centers, and to "stop treating immigrants as criminals" by deprioritizing border enforcement. During the Democratic debate last week, Booker endorsed decriminalizing illegal immigration.

Booker would broaden the definition of a legal asylum claim to cover gang violence and domestic abuse victims and expand migrants' access to attorneys that can guide them through U.S. immigration courts.

"By adopting evidence-based non-profit alternatives to detention and ensuring that detention is used as a last resort, Cory’s goal would be to virtually eliminate immigration detention, with limited exceptions if there is a risk to public safety or flight risk," Booker's plan says.

The proposal would attempt to lower immigration by targeting "corruption, violence, poverty, and climate change" in the countries that are the source of the majority of illegal immigrants into the U.S.

The plan would also legalize "dreamers," migrants who entered the U.S. illegally as children.

Booker appeared on CNN Tuesday morning to defend his plan.

"Remember, this is a crisis that Donald Trump has created through executive action, not through the things that Congress has done," Booker said. "He started and created a crisis with executive action, I will end it with executive action doing things that reflect our values."