During his introduction of Hillary Clinton at a Nebraska rally Monday, Warren Buffett laid down the challenge to Donald Trump.

On releasing his tax returns, Buffett said:

And so that’s why I’d like to make him an offer – an offer I hope he can’t refuse. Donald Trump at one point – he says various things at different times, but at one point, and I think he said it several times – he said he can’t do it, can’t release it because he’s under audit. Now, I’ve got news for him: I’m under audit too. And I would be delighted to meet him anyplace, anytime between now and election. I will bring my tax return; he can bring his tax return. Nobody’s going to arrest us. It is not – there are no rules against showing your tax returns. And just let people ask us questions about the items that are on there.

How many of you would be afraid to have your tax return made public? Yeah, it is not – no, no. You’re only afraid if you’ve got something to be afraid about. And you’re not – he’s not afraid because of what – of the IRS. He’s afraid because of you. So I will meet him in Omaha, or Mar-a-Lago, or he can pick the place – anytime between now and election. I’ll bring my return; he’ll bring his return. We’re both under audit. And believe me, nobody’s going to stop us from talking about what’s on those returns. And send the word to him, if you will.

Buffett didn't stop there. He was on a roll. After mocking Trump's "only I can fix things" grandiose statement, he eviscerated it with Trump's own record.

Now, I think when somebody makes a statement like that, you should look at his record when he has appealed to the American public before. Now, Donald Trump has been in a lot of businesses, he’s had a lot of bankruptcies, but usually that’s just involved borrowing money from the American public. But in 1995 – to my knowledge it’s the only time – Donald Trump went to the American people and he said, ‘Join me – I’m a winner. Join me and invest in my company,’ Trump hotels and casino resorts. It’s the only time he asked the public to join, but now you got a chance to join the great man in this investment. That was in 1995. They listed on the New York Stock Exchange, and Mr. Trump very modestly made the ticker symbol DJT. Guess what that’s for? So he names the company after himself, or he gets the ticker symbol after himself. In the next 10 years, the company loses money every year – every single year. The – he takes out $44 million in compensation during that period.

If you – in 1995, when he offered this company, if a monkey had thrown a dart at the stock page, the monkey on average would have made 150 percent. But the people that believed in him, that listened to his siren song, came away losing well over 90 cents on the dollar. They got back less than a dime. And you know the history of his enterprises where he was borrowing money where one time after another, he went into bankruptcy. I’ve really never known another businessman that brags about his bankruptcies. I mean, and it – to tell you the truth, why not? I mean, it’s his claim to stardom. I don’t know anybody else that’s had six bankruptcies, but there he is.

Whatever you may think of Warren Buffett, when it comes to his investment expertise, he is golden, well-respected, and rarely questioned. This indictment coming from him is even more awful because he knows what he's talking about.

And then he came to the finale, where he likened Trump to Joseph McCarthy:

Now, the young son of Mr. and Mrs. Khan died a dozen or so years ago. In that dozen of years, we’ve employed a lot of people. I’ve had fun doing it. We’ve made money just like Donald Trump has made. I have made no sacrifice. No member of my family has gone – no member of the Buffett family has gone to Iraq or Afghanistan. No member of the Trump family has gone to Iraq or Afghanistan. We’ve both done extremely well during this period, and our families haven’t sacrificed anything, and Donald Trump and I haven’t sacrificed anything. But how in the world can you stand up to a couple of parents who have lost a son and talked about sacrificing because you were building a bunch of buildings?

I mean, that is – when I heard that, my mind went back – and this goes back before most of you were born – but they went back to the McCarthy hearings. And at the time of the McCarthy hearings – at the time of the Senate McCarthy hearings with the Army, Joe Welch had a young assistant of his maligned by Senator McCarthy, and McCarthy went on and on, and implying this guy was a communist and doing all kinds of things. And finally Joe Welch couldn’t take it anymore and he said, and I’ll quote him, ‘Have you no sense of decency, sir?’ And I ask Donald Trump, have you no sense of decency, sir?

I might add – I’d just add one thing. McCarthy’s career went straight downhill after that.

Yes, Buffett is a billionaire. But he's one of the few who recognizes that his success depends on the success of all of us. His speech eviscerating Trump was a sight to behold. You can watch it in its entirety above.