President Trump’s decision to unilaterally cancel funding for foreign aid on the eve of a government funding deadline is a dare. He is forcing Democrats to choose one of two options: either fund his government, which he could unilaterally defund in the future, or shut down the government to appease their base. 

Welcome to Washington, where members of Congress are returning from their summer recess on Tuesday to a city that is in for a bit of chaos. Ten alleged victims of Jeffrey Epstein will appear on the Capitol’s steps this week. Congress will be forced to vote on a resolution empowering the president to maintain control of Washington, D.C.’s law enforcement. Democrats will have to decide if they want to fight, or just go along to get along in respect of keeping the government open. 

What may blow some wind into the sails of those Democrats who want to take the path of fighting is that Mr. Trump is already unilaterally defunding certain programs that were made whole through the bipartisan appropriations process. 

On Friday, the president’s Office of Management and Budget announced that it had issued what is known as a “pocket rescission.” The president has the authority to send funding cancellation requests to Congress — as Mr. Trump did in June, which led to the defunding of PBS and NPR. Congress must then vote within 45 days. That is called a “rescission,” and it is permitted under federal statute.

A pocket rescission is different, however. When the end of the fiscal year — September 30 — is fewer than 45 days away, then the executive branch can simply cut federal funds on its own, the Trump administration argues. The $5 billion that was unilaterally cut on Friday was primarily for foreign aid programs, according to a fact sheet provided by the White House. 

Democrats were quick to denounce the move as “plainly illegal,” given the constraints placed on the executive by the Impoundment Control Act of 1974 and the unanimous Supreme Court decision in Train v. City of New York, which affirmed that presidents may not unilaterally impound funds. 

The move by the president puts the Democrats in an especially tight spot, given their consternation over whether to fight with Republicans ahead of the government funding deadline of September 30. The GOP will need 60 votes to get any funding deal through the Senate, and Speaker Mike Johnson may need Democratic help in the House if hardline conservatives refuse to vote for any spending compromise. 

Senator Charles “Chuck” Schumer — who caved in March to Republican demands that he back a party-line funding bill and immediately saw his approval rating plummet — raged at the president’s pocket rescission in a statement on Friday. 

“As the country stares down next month’s government funding deadline on September 30th, it is clear neither President Trump nor Congressional Republicans have any plan to avoid a painful and entirely unnecessary shutdown,” the Senate Democratic leader said.

“It doesn’t have to be this way. Reasonable Republicans don’t have to go along with the madness.

“Democrats stand ready to work with anyone to help American families, lower health care costs and secure our communities. But if Republicans are insistent on going it alone, Democrats won’t be party to their destruction,” Mr. Schumer added. 

When Senate Democrats return to Washington this week and host their weekly caucus lunch on Wednesday, it is an odds on bet that the issue of rescissions and impoundment will be among the topics discussed. 

Mr. Trump’s rescissions package earlier this summer and his new pocket rescission have handed an example to those liberal lawmakers who want to fight. Over the next four weeks, as they meet for lunch weekly, the members of the caucus need simply to point to these rescissions package to prove to their more moderate friends that Republicans will do this all over again.  

Senator Christopher Murphy has already expressed his frustration in a rather animated way to one of his colleagues. In a viral moment earlier this summer, Mr. Murphy was seen arguing on the Senate floor with Senator Katie Britt. Mr. Murphy, a Connecticut Democrat, and Ms. Britt, an Alabama Republican, are the top lawmakers on the Senate subcommittee for homeland security appropriations. 

“I was saying to her, ‘How on Earth are we going to write a bill to fund the Department of Homeland Security when the president is engaged every single day in illegal activity?’” Mr. Murphy told the Bulwark after a video of the incident went viral. 

“Why would I trade baseball cards with my friend if he tells me I’m going to break into your house tomorrow night and steal my cards back?” he explained, laying out the liberal case for continuing the fight.