It has been about 12 hours since House and Senate negotiators reached a tentative deal to avert another government shutdown, and President Trump still hasn’t issued his all-important endorsement.

That may be because this deal is a pretty bitter pill to swallow. In fact, it’s probably a worse deal than Trump would have gotten if he had never shut down the government in the first place.

The deal as laid out does include some border fencing — $1.375 billion worth, or 55 miles. That’s well shy of the $5.7 billion and 200 miles in wall funding he demanded that led to the shutdown, but it’s not nothing. Trump could argue that he got something out of the 35-day government closure.

But only if you ignore two very important things.

One is that this compromise includes a concession to Democrats, too: a reduction in the number of detention beds. As The Post’s Erica Werner, Damian Paletta and Sean Sullivan report:

The deal omits a strict new cap Democrats had sought on immigrants detained within the United States — as opposed to at the border. At the same time, it limits overall levels of detention beds maintained by the U.S. Immigration and Customs Enforcement agency, although GOP aides said ICE would have enough money and flexibility to maintain its current detention levels and add more when needed.

But the bigger issue is this: The amount of funding is actually shy of the original deal Republicans and Democrats reached last year that Trump rejected. At that time, the spending bill for the Department of Homeland Security included $1.6 billion for 65 miles of fencing, both slightly more than the current tentative deal.

This was the deal on the table (it passed 26 to 5 in the Senate Appropriations Committee in June) when Trump initially began demanding $5 billion for his wall. He’s now getting slightly less than that $1.6 billion while also making a concession to Democrats on detention beds.

This is a big reason the deal was almost immediately rejected by Trump’s most conservative supporters. Sean Hannity called it “garbage,” Ann Coulter retweeted a bunch of people deriding the deal, and House Freedom Caucus Chairman Mark Meadows (R-N.C.) texted to The Post: “This does not represent a fraction of what the president has promised the American people. ... I don’t speak for the president but I can’t imagine he will be applauding something so lacking.”

But even Meadows has conceded that Trump has almost no leverage left in this shutdown debate. Republicans, including Meadows, have signaled they aren’t prepared to shut down the government again at the Friday deadline. Without that, Democrats have no real reason to make concessions. Meadows has said he would support a regular, clean government funding bill if no deal can be reached.

That’s a pretty attractive fallback if you’re a Democrat. Democrats have now put Trump in the unenviable position of accepting a deal that is worse than what he began with if he wants wall funding, or rejecting the deal and risking congressional Republicans signing off on something with no wall funding, possibly leading to a veto standoff with his own party. And Republicans have put this deal on the table knowing they can’t really do any better, given their leverage was sapped by the shutdown.

For Trump’s part, he seems increasingly intent on moving past this debate and basically arguing that the wall is already being built. At a rally in El Paso last night, signs read “Finish the wall” instead of “Build that wall,” though there’s been no real shift in wall funding under his watch. It also appears he might still try to declare a national emergency to fund the wall, even if the current deal is agreed to.

But it’s all rather transparently geared toward saving face at this point, rather than winning the debate. Assuming Republicans can’t get anything more out of this deal than they have right now, it will be quite the capitulation. Trump could have taken $1.6 billion and/or declared a national emergency last year, before all this went down; he will have gotten basically nothing for shutting down the government for 35 days.

And he might just have to take it.