Trump made the construction of a wall to stem illegal immigration from Latin America central to his successful 2016 campaign for the presidency.
The tug-of-war over funding for the barrier caused a record 35-day federal government shutdown beginning on December 22, 2018, and lawmakers have thus far allocated only $1.4 billion to pay for fencing and other barriers along the border. The lawsuits question the urgency of Trump's emergency declaration, and asks the court to halt wall construction work that the Defense Department said could start as soon as May 25.