We've known for a while that the White House ignored Sally Yates's warning about Michael Flynn. Now we come to find out that it also ignored an earlier warning from President Barack Obama himself.

And the White House's explanation for it is oh-so-Trump: It viewed the warning as sour grapes from a loser.

Yates testified Monday that she warned White House counsel Don McGahn in late January about Flynn lying and potentially being compromised — weeks before the situation blew up publicly and Flynn was forced to resign as President Trump's national security adviser. And earlier Monday, we found out that Obama also warned Trump in their post-election meeting against hiring Flynn, a former Obama appointee.

In a briefing Monday afternoon, White House press secretary Sean Spicer weighed in on the latter case, and he suggested that Obama's advice was taken with a grain of salt because Flynn had excoriated Obama during the 2016 campaign. Spicer wasn't quite so blunt, but it was clear that Obama's comments were at least somewhat dismissed as the complaints of a loser.

Here's what Spicer said:

SPICER: It's true that President Obama made it known that he wasn't exactly a fan of General Flynn's, which is — frankly, shouldn't come as a surprise to anyone, given that General Flynn had worked for President Obama, was an outspoken critic of President Obama's shortcomings, specifically as it related to his lack of strategy confronting ISIS and other threats around that were facing America.

QUESTION: If a sitting president raises the name of one individual, why wouldn't that give the president-elect pause? I understand what you're saying — the caveat about the fact that he campaigned against Hillary Clinton, et cetera. But wouldn't that give the incoming president pause?

SPICER: I don't know that I agree with your characterization. He made it clear that he wasn't a fan of his, and I don't think that should've come as a surprise, considering the role that General Flynn played in the campaign, criticizing his …

QUESTION: So, it didn't give him any pause at all?

SPICER: No, I think if you know what we knew at the time, which is that the security clearance that he had, had been re-approved in April of that year, and they took — not only did they re-approve it, but then they took no steps to suspend it. So, the question has to be what did they do if they had real concerns beyond just not having — you know, not liking him for some of the comments that he made.

Spicer's point here makes some logical sense: Basically, if Obama knew Flynn was such a liability, why didn't he do something more than warn his successor about it? As Philip Rucker reports, though, Obama didn't offer a damning reason, so much as “a confluence of red flags,” according to a former Obama administration official: Flyinn's job performance, his comments about Islam, and his attendance at an event hosted by Russian state-sponsored television station RT in Moscow.

But the other part of Spicer's comments says a lot about how the Trump team conducts business. Then-President-elect Trump apparently took a warning from the sitting president of the United States not to hire a specific adviser and dismissed it as partisan politics. He didn't think it was all that serious because he thought Obama was just sore about Flynn attacking him. And he apparently didn't see it as any reason to increase vetting of Flynn beyond his security clearance.

In Trump's black-and-white world, there are only winners and losers; Flynn was a winner, and Obama was a loser bent on evening the score.

President Barack Obama meets with President-elect Donald Trump in the Oval Office on Nov. 10, 2016. (Pablo Martinez Monsivais/AP)

Similar warnings from Yates also were apparently discarded — even though she cautioned that Flynn had lied to the White House and could be vulnerable to blackmail by Russia because of it. She issued that warning on Jan. 26; Flynn wasn't forced to resign until more than two weeks later, on Feb. 13. By that point, it had become public that he had spoken with the Russian ambassador about sanctions — potentially illegally — and lied to Vice President Pence about it.

We don't know why that warning was ignored, but it seems entirely possible that Yates's cautions were dismissed for similar reasons as those for Obama's. Yates, after all, was an Obama appointee serving as acting attorney general before Trump's pick, Jeff Sessions, could be confirmed. And just four days after she issued the warning about Flynn, she directed the Justice Department not to enforce Trump's controversial travel ban. She was quickly fired.

How the White House could have failed to heed Yates's damning warnings about Flynn is particularly puzzling, but I suppose this is as good a theory as any.

Regardless of whether the actual reason, the explanation for dismissing Obama's warnings is plenty telling. The White House had multiple, relatively early warnings about how the Flynn situation could blow up in its face. It heeded neither of them — in part, at least, because it declined to take the cautioning seriously — and it wound up paying the price.

The White House has shown on plenty of occasions that it is hardly the well-oiled machine it sometimes claims to be. This is turning out to be Case Study No. 1 in that.