While Trump and Democrats argue, a reported 800,000 federal employees are furloughed or are working without pay because the government is shut down over the border wall funding dispute.

Jonathan Ernst / Reuters

On the seventh day of a government shutdown, President Donald Trump said Friday that if Democrats don't vote to fund his wall he will order the closure of the border with Mexico — a highly dramatic move that would cost the US billions of dollars in trade and potentially worsen the ongoing humanitarian crisis there. "We will be forced to close the Southern Border entirely if the Obstructionist Democrats do not give us the money to finish the Wall & also change the ridiculous immigration laws that our Country is saddled with," he wrote in a series of tweets.

Trump's threat is the latest in a series of conflicting positions about how he'll fund his proposed wall and who is responsible for the government shutdown, which will continue at least until Congress returns on Jan. 2. Meanwhile, nearly 800,000 federal workers are furloughed or are at their jobs but not getting paid. The government is advising some federal employees to negotiate with landlords and creditors if they're not able to pay rent and debt. It's also not the first time Trump has warned he may close the border. He threatened to do so in October before the midterm elections to prevent the so-called caravan of Central American migrants from reaching the US. But it is the first time the president has used the ultimatum as a negotiation tactic with Democrats, who oppose his bid to use US taxpayer dollars to fund the wall he vowed repeatedly Mexico would pay for. "Either we build (finish) the Wall or we close the Border," he wrote.



Paul Ratje / AFP / Getty Images The border fence near New Mexico's Highway 9, near Santa Teresa on Dec. 23, 2018.

Republicans still control both houses of Congress but require Democratic support in the Senate to overcome the 60-vote filibuster requirement. Democrats will take over the House of Representatives on Jan. 3, when Rep. Nancy Pelosi becomes Speaker. The president does have the legal authority to close US ports of entry or order heightened inspections that would lead to lengthy delays. President George W. Bush ordered the extra security measures after 9/11, leading to a partial border closure, according to USA Today, while President Ronald Reagan shut the border in 1985 in response to the death of a DEA agent in Mexico.

But closing the border might worsen an existing humanitarian crisis, with thousands of Central Americans already waiting in squalid conditions in Tijuana as they await processing of their asylum claims at the US port of entry. Any move to do so would also have enormous effects on US trade, crippling companies that import from and export to Mexico, the third largest US trading partner. Some $1.7 billion of two-way trade occurs every day with Mexico in addition to hundreds of thousands of legal border crossings, according to the State Department. Quartz found that in July some $42 billion worth of goods crossed the border, with Texas, California, and Michigan being the states that saw the most trade with Mexico. "Closing the US-Mexico border would wreck the Texas economy," Rep. Joaquin Castro, Democrat of Texas, said on Twitter. In his tweets on Friday, Trump said he wasn't concerned about trade being harmed, citing a protectionist claim that closing the border would return the country to the days before the North American Free Trade Agreement and bring the car industry back to the US. "I would consider closing the Southern Border a 'profit making operation,'" he wrote. But in addition to ignoring the short-term effects of closing the border, Trump's claim does not consider the economic impact on US exporters. Trump previously said that he will take responsibility for the government shutdown if the wall does not get funded. Then he changed his tune once it happened, blaming Democrats. Asked on Fox News whether the president was serious about closing the border, acting chief of staff Mick Mulvaney said, "I think he is." "That is why the government is closed," Mulvaney added, "because the president is not willing to give up on the southern barrier."

Andrew Caballero-Reynolds / AFP / Getty Images The White House amid the ongoing government shutdown on Thursday.