Title 42 is part of federal legislation relating to public health issues. It gives the government the power to take emergency measures – for example, to stop communicable diseases.
The rule has been in place for decades but was adopted by the Trump administration in connection with the covid pandemic in 2020. The aim was said to be to stop the spread of Covid-19. With Title 42, immigration authorities have been able to return migrants at the border, without examining their reasons for asylum. The number of migrants is now expected to increase sharply.