The Left runs out of excuses for not securing the southern border.

Obstructionist open-borders Democrats will promptly file a lawsuit to halt the building of a desperately needed wall on the nation’s porous multi-state border with Mexico if President Trump declares a national emergency to move forward with construction, the new chairman of the House Armed Services Committee is threatening.

White House aides have reportedly prepared an executive declaration that gives the president the ability to redirect billions of dollars in military construction and flood-control funds.

“There would immediately be a lawsuit,” Rep. Adam Smith (D-Wash.) told C-SPAN. “Taking billions out of the Pentagon’s military construction budget would be a big problem, and there’s bipartisan opposition to it.”

Using funds for the Army Corps of Engineers’ flood-control programs for the wall would also be “problematic,” Smith said.

“We really have no choice but to build a powerful wall or steel barrier,” Trump said Friday as he signed fiscal legislation temporarily reopening the portions of the federal government that had been shut down since before Christmas.

“If we don’t get a fair deal from Congress, the government will either shut down on Feb. 15 again or I will use the powers afforded to me under the laws and the Constitution of the United States to address this emergency.”

Legal experts say the president can call upon the National Emergencies Act, a statute President Gerald Ford signed into law in 1976, to get construction of the wall underway.

President Trump has already invoked the National Emergencies Act three times in his tenure, according to ABC News. President Barack Obama invoked the statute no fewer than 10 times.

Left-wing constitutional law professor Jonathan Turley confirmed in a recent column Trump has the legal authority to act.

“Congress expressly gave presidents the authority to declare such emergencies and act unilaterally,” Turley wrote.

The National Emergencies Act gives presidents sweeping authority as well as allowance in federal regulations to declare an “immigration emergency” to deal with an “influx of aliens which either is of such magnitude or exhibits such other characteristics that effective administration of the immigration laws of the United States is beyond the existing capabilities” of immigration authorities “in the affected area or areas.” The basis for such an invocation generally includes the “likelihood of continued growth in the magnitude of the influx,” rising criminal activity, as well as high “demands on law enforcement agencies” and “other circumstances.”

“Democrats,” Turley wrote, “have not objected to use of this authority regularly by past presidents, including roughly 30 such emergencies that continue to this day. Other statutes afford additional emergency powers.”

Chairman Smith said lawmakers may revisit the National Emergencies Act now that the president isn’t a fellow Democrat.

“I think there is going to be a bipartisan effort to take a look at that 1976 law and see if it granted the president too much power,” he said.

Smith said his committee will examine whether it is “necessary to have active-duty troops at the border.” Smith said his colleagues want to make sure the military is not used for domestic law enforcement.”

Of course, the president has obvious authority under the Constitution as Commander-in-Chief of the armed forces to protect the nation’s borders. Stopping an invasion by illegal aliens isn’t domestic law enforcement, but Democrats are running out of excuses for not giving Trump what he wants, which happens to be his signature 2016 campaign promise.

The dispute over funding for the wall is why the federal government partly shut down for five weeks.

The GOP-controlled House of Representatives voted 217 to 185 on Dec. 20 for a spending bill with $5.7 billion for the wall. The measure floundered in the Senate and the partial shutdown got underway Dec. 22. The Senate remains in Republican hands but the House is now controlled by Democrats.

President Donald Trump signed a bill Jan. 25 to reopen the government for a three-week period, dropping his demand that Congress appropriate funding for the wall before restoring the government to full functionality until Feb. 15 after which the government could partially shut down again. Trump said he’ll use the time to continue to push lawmakers for money for the wall.

“This was in no way a concession,” Trump tweeted Friday. “It was taking care of millions of people who were getting badly hurt by the Shutdown with the understanding that in 21 days, if no deal is done, it’s off to the races!”

The new Democrat majority in the House isn’t even pretending to negotiate in good faith with Trump.

They correctly view the wall as an existential threat to their party and despite their endless whining and mockery of the idea of the wall, they know its construction would slow the flow of illegal aliens into the country and impede the growth of the party’s electoral base.

Trump faced strong criticism from some conservatives for backing off his wall-funding demand and signing legislation to re-open the government in full.

But Trump has posted several tweets in recent days reinforcing his seriousness about getting the wall built.

“Only fools, or people with a political agenda, don’t want a Wall or Steel Barrier to protect our Country from Crime, Drugs and Human Trafficking. It will happen - it always does!” he tweeted Jan. 26.

Along with an informational video from the RNC, Trump tweeted “BUILD A WALL & CRIME WILL FALL!” on Jan. 27.

The same day he tweeted:

“After all that I have done for the Military, our great Veterans, Judges (99), Justices (2), Tax & Regulation Cuts, the Economy, Energy, Trade & MUCH MORE, does anybody really think I won’t build the WALL? Done more in first two years than any President! MAKE AMERICA GREAT AGAIN!”

Trump also took the unusual step of criticizing two Fox News reporters, John Roberts and Gillian Turner, for, in his view, bungling news coverage of wall negotiations.

“Never thought I’d say this but I think @johnrobertsFox and @GillianHTurner @FoxNews have even less understanding of the Wall negotiations than the folks at FAKE NEWS CNN & NBC! Look to final results! Don’t know how my poll numbers are so good, especially up 19% with Hispanics?”

The congressional standoff over wall funding continues.