(CNN) Eight days ago, President Donald Trump had this to say about the possibility of a government shutdown if Congress didn't give him $5 billion to begin construction on his border wall:

"I tell you what, I am proud to shut down the government for border security, Chuck, because the people of this country don't want criminals and people that have lots of problems and drugs pouring into our country. So, I will take the mantle. I will be the one to shut it down. I'm not going to blame you for it. The last time you shut it down it didn't work. I will take the mantle of shutting down and I'm going to shut it down for border security."

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On Wednesday morning, White House senior counselor Kellyanne Conway sounded a very different note, suggesting that if Congress passed a short-term resolution to keep the government open then Trump would "take a look at that certainly." Added Conway: "A short term [continuing resolution] -- or a CR that goes through February 8 keeps the government up and running but that doesn't mean the President is backing down from an essential promise, not a campaign promise, a promise as President of the United States and our commander in chief to keep us safe."

Uh.......

Trump himself sounded a similarly defensive -- and nonsensical -- note in a tweet on Wednesday. "Mexico is paying (indirectly) for the Wall through the new USMCA, the replacement for NAFTA!" tweeted the President . "Far more money coming to the U.S. Because of the tremendous dangers at the Border, including large scale criminal and drug inflow, the United States Military will build the Wall!"

This is a classic case of overcompensation.

In order to convince you -- and themselves -- that Trump's willingness to sign a short-term continuing resolution to avoid a government shutdown isn't a capitulation of his former tough talk about doing whatever it takes to get funding for the border wall, both the President and Conway are suggesting that who you see and what you hear isn't actually true.

Trump is going to get the wall money! And no matter what, Mexico is going to pay for it! Somehow!

At the moment, neither of those things are true. The truth? Trump made a promise -- and kept reiterating a promise -- he is now going back on.

And his backing down this time has real consequences. Remember that Democrats take control of the House come January. Which means that the next time we have a government funding fight like this, it will be with divided government. And it's VERY hard to see how Trump will get the $5 billion+ he wants for a border wall with Democrats in charge in the House. Heck, he hasn't been able to get the money he wanted for the wall over the last two years, with Republicans in charge of everything!

Go back to the spring. Congress was, yet again, bumping up against a hard deadline to either fund the government or have it shut down. Trump had pledged to sign no new omnibus spending bill that didn't include substantial funding for his border wall. Even after the legislation had been largely agreed to by Congress -- without the expenditure Trump wanted for the wall -- he threatened to veto it via tweet

"I am considering a VETO of the Omnibus Spending Bill based on the fact that the 800,000 plus DACA recipients have been totally abandoned by the Democrats (not even mentioned in Bill) and the BORDER WALL, which is desperately needed for our National Defense, is not fully funded," he wrote

That turned out to be an empty threat -- as Trump eventually signed the omnibus bill. But when he did so, he issued another threat for the next shutdown showdown to come in the fall.

"I say to Congress: I will never sign another bill like this again," Trump said at the time . "Nobody read it. It's only hours old. ... (It's) the second-largest ever. President Obama signed one that was actually larger, which I'm sure he wasn't too happy with either."

In the run-up to this latest deadline, which was initially December 7 before Congress -- wait for it -- passed a two-week extension, Trump and Republican congressional leaders were resolute that either Trump got the money he wanted for the wall or the government shut down.

"I don't do anything ... just for political gain. But I will tell you, politically speaking, that issue is a total winner. People look at the border, they look at the rush to the police, they look at the rock throwers and really hurting three people, three very brave Border Patrol folks — I think that it's a tremendous issue, but much more importantly, is really needed. So we have to have border security."

And yet, as the deadline -- midnight Friday -- approaches, Trump appears to be ready to blink. Again.

Which is fascinating given not just his rhetoric over the last few months on the necessity of the wall but how central the construction of the wall was to his victory in the Republican presidential primary process in 2016.

Without his promise to build a wall along the country's southern border -- and make Mexico pay for it -- there likely would never have been a "President Donald Trump." The wall became a stand-in for everything Trump supporters loved about him: A willingness to talk tough, to buck political correctness and to stand up for Americans. Aside from the "lock her up" chants directed at Hillary Clinton, the "build that wall" cheer was the largest and loudest rallying cry at nearly every Trump campaign rally in 2016.

And now, almost certainly, Trump will, again, go back on that pledge. Despite insisting that after the last time he went back on the pledge he would never do it again.

Whoops!

Does Trump's likely (re)capitulation on wall funding have any measurable political impact among his political base? The easy answer is "no" -- because, as the last two years have shown, almost nothing has any measurable political impact on Trump's base. They appear to be with him no matter what, entirely unaffected by outside events.

If -- and this is a big and shaky "if" -- there ever was an issue that made Trump's base (or a part of it) rethink its support for him, the inability of the President to wring the money needed for the wall out of Congress might be it. It is a foundational principle of Trumpism that Trump just keeps doing very un-Trump things about: Like giving in. Again. And this time with the real possibility that there will never be as good a chance to get even close to the amount of money out of Congress that Trump insists is necessary to build the wall.