The first test of wills between leaders of split government arrives three weeks early, and it might produce nothing other than a government shutdown. Nancy Pelosi and Chuck Schumer will meet with Donald Trump this morning to discuss the remainder of the 2019 budget, which still has not formally funded the departments of Homeland Security, State, and Justice. Trump has adamantly demanded $5 billion in funding for his border wall, and Pelosi and Schumer are just as determined not to give it to him:

Trump is scheduled to meet in the Oval Office on Tuesday morning with House Minority Leader Nancy Pelosi and Senate Minority Leader Charles E. Schumer less than two weeks before a deadline to pass legislation to keep the Department of Homeland Security and several other agencies funded and open beyond 11:59 p.m. on Dec. 21. …

The high-stakes meeting was delayed one week as Washington paused for the funeral of former President George H.W. Bush. But those somber events only delayed the inevitable: a partisan clash and public relations fight that will pit Trump’s demand for $5 billion for a southern border barrier against the Democrats’ staunch opposition to one penny above a $1.6 billion border security proposal in a Senate-passed spending bill.

Schumer and Pelosi ramped up the rhetoric in a Monday statement, saying Trump “knows full well that his wall proposal does not have the votes to pass the House and Senate, and should not be an obstacle to a bipartisan agreement.”

Roll Call argues that Trump’s legal woes undermine his position, “complicating his talks” with the Democratic leaders. Why that should matter is not entirely clear. If anything, Trump’s more likely to stick to his guns on immigration policy and the wall to keep his base engaged; moderates aren’t going to flock to him under these circumstances if he backs down. Besides, Trump’s leverage in this case remains the same — the Senate and his own ability to veto a budget that doesn’t fund his priorities.

Trump raised the curtain on this morning’s meeting by declaring on Twitter that he’d get the wall built, with or without Pelosi. If Congress won’t provide specific funding for the bill, then Trump said he’d have the Pentagon do it:

That might be one reason that Trump reversed himself on the military budget this week. Trump had complained before about spending at the Pentagon, but now the president has agreed to back Defense Secretary James Mattis on getting a budget boost:

President Donald Trump has told Defense Secretary Jim Mattis to submit a $750 billion budget proposal for fiscal 2020, in a reversal from his pledge to trim defense spending, two people familiar with the budget negotiations have told POLITICO.

The $750 billion figure emerged from a meeting Tuesday at the White House among Trump, Mattis and the Republican chairmen of the House and Senate Armed Services committees, both people said.

“It’s 750. Secretary Mattis secured that over lunch with the president,” an administration official said of the meeting, speaking on condition of anonymity to discuss a figure that has not yet been announced. Mattis was joined by Sen. Jim Inhofe (R-Okla.) and Rep. Mac Thornberry (R-Texas). “That’s the top line.”

That would dwarf the $733 billion budget proposal Mattis and other top military leaders have been fighting to preserve and would represent a stunning about-face for a president who recently called the fiscal 2019 top line of $716 billion for defense spending “crazy.” In October, Trump said the defense figure for 2020 would be $700 billion, a roughly 5 percent cut in line with decreases planned for other agencies.

Hmm. That’s a $34 billion increase from FY2019, an increase of 4.3% in a single year. It’s also easy to fit a $25 billion wall in that increase and still have some left over for other military priorities. Could Trump try to shift funds from military spending on the basis of national security? If Congress doesn’t earmark all the funds for specific purposes — a practice that has gone out of style, thanks to congressional corruption around pork-barrel politics — then it’s arguably possible, although that would touch off a huge fight with the House.

Expect that topic to come up when Donald meets Nancy and Chuck this morning. The two Democrats can’t afford to give Trump a win today, and Trump can’t afford any more delays on his border wall. An end-around through the Pentagon might be the only resolution for the standoff … for Trump, anyway.