What did Donald Trump do today?

He made sure there was a check on Elon Musk's power—Elon Musk.

Press Secretary Karolina Leavitt was asked today how Trump would ensure that Elon Musk, who has been given an essentially unlimited portfolio of presidential power, would be kept from potential conflicts of interest. Musk owns several businesses which could not exist without massive government contracts (like SpaceX) or subsidies (like Tesla), and now has direct and personal control over the payment apparatus of the United States government. This also gives him access to proprietary information about his competitors.

Leavitt's answer was simple: Musk would be in charge of making sure that Musk recused himself from potential conflicts.

"Conflict of interest" has been a dead letter in the Trump White House since his first term. Trump refused to divest himself of any of his businesses, wrote tax laws to benefit himself personally, appointed a vast array of his relatives to government positions, made millions from charging his own Secret Service detail the maximum room rate at hotels he owned, hawked Trump-branded merchandise from the White House, and even tried to force the G-7 summit to happen at one of his golf courses. But even by those standards, today's admission about Musk was startling.

Trump's increasing deference to Musk comes as Musk himself is becoming a toxic political liability, unifying Trump's political enemies and deeply worrying his allies. Musk's own approval ratings have plummeted with both Democratic and Republican voters over the last few days. The ratings-obsessed Trump is normally exquisitely sensitive to that kind of thing, and has fired subordinates for less—at least, when he felt he was able to.

Why does this matter?

• The richest and—arguably—most powerful person in the world shouldn't be allowed to use the United States government to make himself richer and more powerful.