There was every reason to hope last week that policymakers would work out a deal on immigration and prevent a government shutdown. Donald Trump urged lawmakers to work out a bipartisan agreement, which he vowed to support, explicitly telling them that he didn’t care what was in it.

And so, on Thursday, the president talked to Sen. Dick Durbin (D-Ill.) on the phone, and the Illinois Democrat explained that a bipartisan deal was in place. Trump asked if Sen. Lindsey Graham (R-S.C.) was on board, and Durbin said he was. The president then invited Durbin and Graham to the White House for a meeting to discuss the deal.

Graham and Durbin thought the discussion would be with Trump. Instead, they arrived to discover that far-right opponents of the bipartisan deal – including Rep. Bob Goodlatte (R-Va.) and Sen. Tom Cotton (R-Ark.) – would also be part of the meeting.

The Washington Post reported overnight that the president, after signaling support for the Senate agreement, quickly switched gears, telling the meeting’s participants “he wasn’t interested in the terms of the bipartisan deal that Durbin and Graham had been putting together.” It was at this same meeting that Trump dismissed immigrants from “shithole countries.”

So, what happened? This happened.

[S]ome White House officials, including conservative adviser Stephen Miller, feared that Graham and Durbin would try to trick Trump into signing a bill that was damaging to him and would hurt him with his political base. As word trickled out Thursday morning on Capitol Hill that Durbin and Graham were heading over to the White House, legislative affairs director Marc Short began to make calls to lawmakers and shared many of Miller’s concerns. Soon, Goodlatte, one of the more conservative House members on immigration, was headed to the White House. Trump also called House Majority Leader Kevin McCarthy (R-Calif.) and asked him to come, McCarthy said. Sens. David Perdue (R-Ga.) and Cotton were also invited to rush over.

And this, in a nutshell, is why negotiations with the White House are effectively impossible.

Regular readers may recall that during last year’s drama over health care, it was an open secret that Republicans were terrified of the prospect of Donald Trump negotiating directly with Democratic leaders. The fear, of course, was that the amateur president would sit down Nancy Pelosi and Chuck Schumer, he’d find their pitch compelling; and Trump would end up giving Dems everything they asked for.

Those fears haven’t gone away. In fact, they’ve solidified to the point that some in the president’s orbit believe Trump, uninterested in any of the substantive details of public policy, would’ve been “tricked” into backing the bipartisan immigration deal – and by “trick,” I mean he would’ve listened to Dick Durbin and Lindsey Graham, nodded along as if he were paying attention, and then endorsed their agreement.

Since Miller and far-right lawmakers didn’t want that outcome, they rushed over to the White House to persuade him not to go along with the bipartisan compromise.

The Post’s article added, “Trump’s ping-ponging from dealmaking to feuding, from elation to fury, has come to define the contentious immigration talks between the White House and Congress, perplexing members of both parties as they navigate the president’s vulgarities, his combativeness and his willingness to suddenly change his position.”

No one can say with any confidence what Trump will say, think, endorse, or tweet any given moment. Negotiating with him is pointless, since he’s likely to agree with the last person he speaks to – until someone else walks in the room and convinces him to reverse course.

Indeed, we saw this play out just last week, when Trump briefly endorsed a clean DACA bill proposed by a Senate Democrat, only to have a House Republican remind him that this wasn’t his position.

TPM had a report last week that added, “The president’s tendency to change positions as frequently as he orders Diet Cokes is once again causing a major headache for lawmakers as they attempt to craft policies without a clear idea of what the White House is willing to support. With no agreement yet on whether a DACA deal will be a part of the Jan. 19 spending bill, what the exact status for the 800,000 impacted young immigrants would be, and what forms of ‘border security’ Trump is demanding, the mass confusion is raising the potential for a government shutdown.”

Current funding for the government expires on Friday night. Watch this space.