Over the past few weeks, Donald Trump has given a series of extended interviews with major news outlets, covering topics ranging from foreign policy to the economy to abortion. Those interviews have been intensely revealing. What they have shown is that Donald Trump has no idea what he is talking about on just about anything of relevance to a presidential candidate.

More than that, though, we've learned that Trump refuses to prepare, and will not learn even the most basic factoids, even when a topic is certain to arise during an interview. Instead, he will respond with deliberate provocations, with refusals to answer questions, by altering his "position" repeatedly, by changing the subject, and by ignoring or denying the facts of the subject at hand. He has demonstrated not only that he is a blithering know-nothing, but that he is determined to stay that way.

In the space of just three days last week, for example, Trump—who years ago described himself as "very pro-choice" but has said throughout the campaign that he is now pro-life—managed to take five different positions on abortion.

First he said that, should abortion become illegal, there would have to be some punishment for women who got abortions. Shortly after the statement became public, a spokesperson clarified to say that the issue should be left to states, and that Trump was "pro-life with exceptions." Later that same day, his campaign released yet another statement saying that if abortion were made illegal, doctors who performed the procedures would be subject to punishment, but women would not be. The next day, he shifted again, seeming to indicate that he believes abortion should remain legal, saying that while he would prefer a federalist approach, "the laws are set…and I think we have to leave it that way." The same day, his campaign released another statement saying that Trump merely wants the law to stay the same way until he is president.

Trump's fumbling responses do not reveal what his actual position on abortion is so much as they show that he has no idea what he is talking about, and has never bothered to learn even the most basic talking points about the subject. That is more or less Trump's own explanation for his initial statement that women would need to be punished for getting abortions if the practice were outlawed.

"I've been told by some people that was an older line answer and that was an answer that was given on a, you know, basis of an older line from years ago on a very conservative basis," he said in a CBS interview, when asked about his response. Trump did not know this, or bother to find out. On a controversial topic that was sure to come up in a major interview, Trump chose to simply wing it.

Trump's Impossible Debt Reduction Promises

That appears to be how Trump conducts just about all of his interviews and policy pronouncements. He consults with almost no one except a handful of loyalists, family members, and Alabama Sen. Jeff Sessions, one of the GOP's most restrictionist voices on immigration, and he tends to describe himself as his own chief adviser on both strategy and policy.

So it's no surprise that whenever his answers can be fact-checked, the facts fail to check. In an interview with The Washington Post published over the weekend, for example, Trump said that he would completely eliminate the nation's $19 trillion debt in just eight years. He provided no clear way to do this, except to say that he would renegotiate the nation's trade deals so as to reduce the trade deficit. "The power is trade," he said. "Our deals are so bad."

Trump's promise doesn't pass the laugh test.

To start with, that's just not how trade deficits work. Trade imbalances, which measure the difference in value between a nation's exports and imports, do not represent dollars that the government can simply collect to pay down the creditors. And even if somehow you could, it still wouldn't cover the debt. Plus, that doesn't account for Trump's tax plan, which would represent a nearly $10 trillion increase in the deficit over a decade.

And then there's Trump's repeated promise not to reform Social Security, except through essentially minor reductions in waste, fraud, and abuse. The math simply doesn't add up.

As Jim Tankersly writes at the Post, "Trump could pass his tax cut, monetize the entire trade deficit as additional revenues, somehow eliminate all federal spending except Social Security (which he has said he will protect) and still not pay off $19 trillion of debt in eight years." Nor is it remotely plausible that Trump would reduce the debt through economic growth. As the Center for a Responsible Federal Budget, an organization that is dedicated to reducing federal debt and deficits, notes, Trump's plan would ultimately require cutting non-entitlement spending by about 90 percent, while growing at more than 20 percent each year. To put this in context: Many economists were skeptical when Jeb Bush said that as president the nation would achieve four percent growth.

As with abortion, what we learn from this isn't really what Trump thinks about the issue: Instead, the main takeaway is that Trump doesn't know enough to learn even very basic facts about the subjects he discusses, and could not, in the course of running for president, be bothered to learn them.

Nonsense Policy

In other cases, Trump's responses to questions about policy are so removed from both reality and coherent thinking that they simply defy analysis. In the same Washington Post interview, Trump argued that the real unemployment rate was not 5 percent, as the Bureau of Labor Statistics (BLS)—the government agency that produces the official unemployment rate—says it is, but is instead much higher.

"We're at a number that's probably into the twenties if you look at the real number," he said, suggesting that the official statistic was generated for political purposes. "That was a number that was devised, statistically devised to make politicians — and in particular presidents — look good."

It might be reasonable for Trump to take issue with the official statistic if he had, say, a methodological dispute with the way the BLS produced its estimate. But Trump has nothing of the sort. His sole evidence to support this claim is that "I wouldn't be getting the kind of massive crowds that I'm getting if the number was a real number."

The problem with this is that it is not any kind of evidence at all. It is an inference based on a data point that has nothing to do with his conclusion, an inference that says, basically: Trump's rallies are well-attended, therefore the real unemployment rate is four times what the official statistic says it is. It is as logically sound as the proposition that bananas do not respond to the pull of gravity because Donald Trump often wears red ties. The first part is not true, and although the second part is, it has nothing to do with the first. It is economic policy Dadaism.

Trump's indifference to both fact and reason makes him extremely difficult to argue with. We saw this in a debate earlier this year when Fox News moderator Chris Wallace told Trump that his plan to save the federal government $300 billion by cutting drug spending wouldn't work because the program he wanted to cut only cost $78 billion annually. Trump responded by bringing up some irrelevant details and unrelated issues, being told that they were irrelevant, and then concluding that, because of his superior skills as a negotiator, he could in fact save $300 billion. Trump is completely un-phased by appeals to logic, math, or sense.

And that's what happens when Trump bothers to answer the questions posed to him. Sometimes when interviewers press Trump for further details on questions, he will just change the subject, refusing to answer the question. In a different interview with The Washington Post editorial board, Trump responded to a clear follow-up question about whether or not he would use a tactical nuclear weapon against ISIS with the following: "I'll tell you one thing. This is a very good looking group of people here. Could I just go around so I know who the hell I'm talking to?"

Trump's Dangerous Self-Certainty

What these responses make clear is that Trump boasts a dangerous combination of self-certainty about issues he does not understand and an unwillingness to ever perform even the most cursory review of the issues he discusses. This is not new. It is a core part of his persona. Indeed, Trump seems to have a longstanding belief in his own ability to get up to speed on complex policy issues extremely quickly.

Back in 1984, Trump argued that he should be mediating nuclear arms negotiations between the United States and the Soviet Union, as Jim Geraghty notes. Trump did not have any particular experience with high-stakes international arms treaties, but did not see that as a barrier to his success. "It would take an hour-and-a-half to learn everything there is to learn about missiles," he told The Washington Post at the time. To be clear, Trump was not some nuclear arms expert who merely needed to brush up on new developments: As recently as 2015, he did not know what the nuclear triad is. He simply thought that an hour and a half was all that it would take for him to learn what he needed to learn.

On the other hand, 90 minutes appears to be more than he's spent learning about practically any of the policy issues he's discussed during this campaign.

The GOP is Willing to Support Trump's Ignorance

All of this is, of course, incredibly damning to Trump. But it also reflects poorly on his supporters, the third or so the party's primary voters who seem not to care that Trump is helplessly uninformed. The same goes for the Republican party politicians and leaders who continue to insist that the party will stand behind Trump if he is the nominee.

When Reince Priebus, the Chairman of the Republican National Committee, says that "we are going to support the nominee of our party, whoever it is, 100 percent," what he reveals is that either he believes the party should support someone who has shown over and over again that he is manifestly unqualified to hold the office of president, or he does not believe that Trump's total policy ignorance should be disqualifying. He is saying, essentially, that it's okay, just so long as Trump is running as a Republican. He, and the rest of Trump's backers in the party, are validating Trump and his campaign. Trump may be clueless about politics in many ways, but he knew enough to run under the banner of a party that would support him in his ignorance.