Trump is seeking more than $5 billion to build a wall between the U.S. and Mexico, which he promised supporters he would do while campaigning for the presidency in 2016, while Democrats are opposed to spending any taxpayer dollars on a security measure they assert can be easily breached and is largely symbolic.
An estimated 800,000 federal workers are affected by the shutdown. That figure includes 380,000 people out of work, and more than half working without pay. An additional 4.1 million federal contractors are also affected.