Donald Trump is lying about opposing the Iraq war before it happened. Here’s proof.

Donald Trump has consistently said that he understands foreign policy better than the rest of the Republican field. His proof? He opposed the Iraq war from the start. The only problem was that no one could find evidence of that early opposition — it was clear Trump opposed the war later, after it was a clear fiasco, but he never produced proof of his pre-war prescience.

But it turns out Trump did take a position on the Iraq war prior to the actual invasion. But it wasn't the position he said it was. In 2002, Trump came out in favor of the Iraq war.

The truth came Thursday night, courtesy of Buzzfeed's Andrew Kaczynski and Nathan McDermott. Kaczynski and McDermott looked through old recordings of Trump on the Howard Stern Show, and came up with one hell of a scoop from the September 11, 2002 episode:

Stern: Are you for invading Iraq?

Trump: Yeah, I guess so. I wish the first time it was done correctly.

"Yeah, I guess so" — the words of a true statesman, weighing in on the most important foreign policy question of the 21st century.

Here's the actual audio, in case you had any doubt (Iraq conversation starts at 3:40):

For a normal candidate, this would be a devastating blow to their credibility. This one of the key ways Trump distinguishes himself from his GOP opponents on foreign policy, if not the key argument. It's central to his claim that his unique, Trumpian judgment and intelligence makes him qualified to be commander in chief despite no foreign policy experience and even less knowledge.

And yet, I'm skeptical that it will matter at all.

We've known well before Kaczynski and McDermott's scoop that Trump was lying about his public opposition to the Iraq war; fact checker after fact checker looked into it and found zero evidence that it was happening. As The Atlantic's James Fallows put it, in a piece written four days before the Buzzfeed audio discovery: "Trump. Is. Lying. About. Having. Publicly. Opposed. The. Iraq. War."

Trump has been lying throughout the campaign, both about his issues and his own past record. But the problem is that Trump can just get away with brazenly lying. By virtue of his status in the polls, news outlets are forced to give Trump airtime, and it is very hard to disprove a dedicated serial liar on air if they just commit to their falsehoods. My colleague Dylan Matthews summed up this dynamic well:

Producers know that when you put someone who's likely to spew falsehoods and who's impervious to all attempts to correct them on the air, that person is going to get a lot of opportunities to repeat his falsehoods, and it'll be very hard if not impossible to debunk him. Viewers will get a healthy sampling of lies, and undoing that damage in the space allowed will be nigh impossible.

Matthews was writing in November, but so far nothing has changed. Trump hasn't stopped lying, and there's no evidence that negative press coverage has damaged his campaign.

So while Kaczynski and McDermott have done an extraordinary job finding hard evidence that Trump supported the Iraq, there's a very good chance it won't end up mattering. It's always possible, of course, that this could be the lie that voters finally take notice of. But it would be surprising indeed if Trump finally lost Republican voters because he supported George W. Bush's war.