President Donald Trump took to Fox News on Tuesday morning to defend his flip-flop on labeling China a currency manipulator. And what we got was a perfect little illustration of a president who believes his campaign-trail promises mean basically nothing.


Here’s the exchange with “Fox and Friends” host Ainsley Earhardt:


TRUMP: … Somebody said “Currency manipulation.” What am I going to do? In the middle of him talking with North Korea, I’m going to hit them with currency manipulation? This is the fake media that just does a number. Think of it: He’s working so nicely, many coal ships have been sent back, fuel has been sent back, they’re not dealing the same way. Nobody’s ever seen it like that. Nobody’s ever seen such a positive response on our behalf from China, and then the fake media goes, “Donald Trump has changed his stance on China.” I haven’t changed my stance. China’s trying to help us. I don’t know if they are going to be able to or not, but do I want to start heavy, heavy trade or currency manipulation statements against someone who’s out there trying to stop what could be a very bad situation? You understand that.


EARHARDT: I understand that.


Yes, we all understand that.


Except that the “fake media” didn’t invent anything here. Trump has said repeatedly that he would label China a currency manipulator — as many as a dozen times as a 2016 candidate and three times on Twitter back in 2012, according to the Donald Trump database. This is the definition of him changing his stance; Trump’s contention that it isn’t is complete nonsense.


Trump’s “Contract with the American Voter,” which is still on his campaign website and is labeled a “contract” (!), pledges to do this within 100 days: “THIRD, I will direct the Secretary of the Treasury to label China a currency manipulator.” And here’s what Trump said in late October in Florida: “I blame our politicians for letting this take place. So easy to stop. So easy to stop.”


Except that it’s apparently not so easy to stop, which is really the point here. As Trump has acknowledged — to his credit, perhaps — China plays a significant role in containing North Korea and is otherwise a world power to be reckoned with. Against that backdrop, labeling it a currency manipulator is a dicey move.


But that backdrop was very much the same when Trump made this promise, over and over. And he still made it, over and over.


This is a nice little microcosm of Trump’s repeated flip-flops and contortions. It goes a little something like this:


1. Amateur politician makes big statement (in this case, that China is a currency manipulator)


2. Amateur politician promises to take swift and controversial action (to label China a currency manipulator as president)


3. Crowd cheers


4. Amateur politician repeats promise over and over, to more cheers


5. Amateur politician actually becomes president


6. Amateur politician-president realizes his stance was completely impractical (given China’s role in containing North Korea, among other things)


7. Amateur politician-president can’t understand why people would have taken him at his word in the first place


The arc is completely similar on any number of Trump campaign-trail promises and applause lines: prosecuting Hillary Clinton, repealing Obamacare, attacking Barack Obama for golfing as president, renegotiating the Iran deal, calling NATO obsolete, etc. Trump made big promises and statements on each that proved impractical once he was actually in position to make good on them. So he didn’t even try. And on each one, he simply wants us to grant him a mulligan.


The only conclusions from there are: a) He makes big promises about hugely consequential issues without doing his homework — confirming the belief that he’s in way over his head — or b) He says these things without ever planning to do them — lying to his supporters. It’s the old “Stupid or Liar” theory.


It’s one thing to come across new information as president; it’s another to have been completely unaware of things like China’s role in North Korea while making huge promises as a candidate. That’s Foreign Policy 101 stuff.


And this casual approach to facts and the political and foreign policy realities of the day has cost Trump dearly when it comes to his credibility.


Aaron Blake is a Washington Post columnist.