The legal strategy remains in the theoretical stages, since Trump has so far declined to take such a step — and it’s unclear if he ever will.

But on day 21 of the partial government shutdown — a closure prompted by an impasse over border wall funding — Democrats are prepping for the possibility that Trump will try to sidestep Congress and divert other funds to new wall construction by proclaiming the situation a formal emergency.

ADVERTISEMENT Increasingly, Democratic critics of that maneuver view a lawsuit as their best recourse.

“Let’s get the president’s obsession out of the legislative context, let’s put it into the courts, let’s reopen the government, and we’ll see if he has those powers or not,” Raskin added.

“I think it is a face-saving — a rather desperate face-saving — measure by the president that has very little intellectual underpinning to justify it,” Connolly said.

“And that will be exposed in litigation.”

The comments come as Trump and Democratic leaders have given little ground in their on-again-off-again talks to end the stalemate over border spending.

Roughly 25 percent of the federal government has been shuttered since Dec. 22, and at the stroke of midnight Friday the shutdown will become the longest in the nation’s history.

Trump, whose 2016 campaign hinged on the central promise to build a “big, beautiful wall” at the U.S.-Mexico border, is insisting that the spending package in question include $5.7 billion for new wall construction. Democrats have countered with $1.3 billion for border security that includes new detection technologies, more personnel and the reinforcement of existing walls and fences — but no money to build new barriers.

Trump on Thursday had suggested he would seek to break the impasse by declaring a national emergency at the border, thereby freeing up the $5.7 billion from other programs already funded by Congress.

“If this doesn't work out, probably I will do it,” Trump said Thursday morning. “I would almost say definitely.”

The source of the funding, in that event, seemed to evolve throughout the week, with both the Pentagon and the Army Corps of Engineers floated as potential funding streams.

But on Friday, after a quick visit to the Texas-Mexico border, where Trump said he found evidence of a “crisis,” the president declined to declare the situation an emergency.

“We want Congress to do its job,” he said. “What we're not looking to do right now is national emergency.”

By proclaiming a “crisis,” but not declaring an emergency, Trump invited plenty of criticism from his Democratic detractors, who said the president undermined his own argument. If the crisis is real, the critics said, the emergency designation would necessarily have followed.

Meanwhile, Trump is facing increasing pressure from some conservatives in Congress, who are urging him to make good on his wall promise with an emergency declaration.

“Mr. President, declare a national emergency now. Build a wall now.”

“When he makes a decision, we’ll let you know what we think about it,” Pelosi told reporters Friday evening in the Capitol.

Some Democrats, while critical of an emergency decree as a legal strategy, are also inviting Trump to take that step for a political reason: they see it as the quickest way to reopen the government and get the roughly 800,000 affected federal workers back to getting paid.

“It has the potential for at least allowing Republicans finally to vote to reopen the government,” Connolly said. “He doesn’t know how to get out of the corner he’s boxed himself into.”

Raskin echoed that message on Friday.

“Politically, this may be the best way out of the shutdown,” he said.

“I have some colleagues who think it is a graceful way out of the shutdown; I have some colleagues who think it is a disgraceful way out of the shutdown; but if it’s a way out of the shutdown, then so be it,” he continued. “We need to put our people back to work.”