Illegal immigration, like legal immigration, is happening due to violence and disaster in their home country. Those with family members in the USA are allowed to cross and those without are turned back should they show up at the border unexpectedly.

It is “hidden” refugee crisis and people flee because they have been threatened with death.

The United Nations Refugee Chief believes them. It comes from the power of gangs. And impacts people who are not protected by the government like those living in gang controlled areas.

Drug-trafficking and violence have spread from Mexico down to Central America.

Those terrorized by the major gang back home, flee clandestinely to the USA only to run into the same gang.
https://www.newyorker.com/magazine/2018/01/01/the-teens-trapped-between-a-gang-and-the-law

Removing the Temporary Protected Status endanger these types.