WASHINGTON – The partial government shutdown which began on Dec. 22 is now in its 20th day, and it appears likely to become the longest in U.S. history.

The longest shutdown on record lasted from Dec. 5, 1995, to Jan. 6, 1996, when Republican House Speaker Newt Gingrich and Democratic President Bill Clinton faced off over taxes. But unless there is an unexpected breakthrough, the current shutdown will surpass that mark on Saturday.

The current shutdown became the second-longest ever on Wednesday, surpassing a shutdown during the Carter administration.

About a quarter of the federal and 800,000 workers are affected by the shutdown, which is the result of an impasse between President Donald Trump and congressional Democrats over funding for a barrier on the U.S.-Mexico border.

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Trump argues a barrier – he has backed off demands for a concrete wall – is necessary for national security and to combat what he characterizes as an immigration crisis on the southern border.

Democrats argue Trump's crisis is manufactured to score political points. They have insisted the president agree to reopen the government before continuing negotiations over the most effective way to improve border security.

Negotiations stalled again Wednesday after Trump abruptly left a White House meeting with House Speaker Nancy Pelosi, D-Calif., and Senate Minority Leader Chuck Schumer, D-N.Y. The president is traveling to Texas Thursday to review the situation at the border.

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