Talk of a U.S. government shutdown is again in the air. Funding for the vast menu of federal activities, foreign and domestic, is due to run out after Dec. 8, and Republicans and Democrats in the U.S. Congress are negotiating a spending bill to carry beyond that date. Without a deal, the U.S. will encounter what’s officially called a “spending gap,” which triggers a carefully prescribed, but still disruptive, halt to Washington’s work.1. Why might the government shut down on Dec. 8?Since Oct. 1, when the 2018 fiscal year began, the U.S. has been operating on temporary funding provided by a “continuing resolution” passed by Congress and signed by President Donald Trump. It runs through Dec. 8, and leaders in Congress are negotiating an extension. At the same time, they’re juggling demands from various factions in both parties to stabilize insurance markets, extend a program to protect from deportation some young people brought to the U.S. illegally as children, and raise budget caps for defense spending.