What did Donald Trump do today?

He got very excited about his new top priority, a ceremonial arch.

Last month, shortly after Trump had destroyed the East Wing of the White House, his spokesperson Karolina Leavitt said that building a ballroom on its ruins was Trump's "main priority." The fact that she said this during what became the longest government shutdown in American history, among other more pressing problems, didn't go unnoticed. (Leavitt later insisted she hadn't meant what she said.)

Today, Trump reveled in what may be his new favorite hobby: building a ceremonial arch like Paris's Arc de Triomphe, except—to hear him tell it—bigger and better.  To that end, he said today he'd assigned his top domestic policy advisor the task of building such an arch by the 250th anniversary of independence next year. In fact, Trump said he'd told that advisor, Vince Haley, that it was his top priority: "That's your primary thing."

Building a ceremonial arch is not really "policy." As one columnist put it:

Americans struggling with increased costs due to tariffs imposed by Trump on imported goods – or those whose health insurance premiums are set to double or triple in the coming weeks – might disagree with the president’s claim that the construction of an Arc de Triomphe knockoff should be the main focus of his chief domestic policy adviser. 

There is some historical context Trump doesn't seem to be aware of. The Arc de Triomphe in Paris was commissioned by Napoleon in 1806, when he was already ruling as a dictator and had had about as much success as a military conqueror as he ever would. But his declining military fortunes and decaying empire made it impossible to continue construction, and he was long deposed and dead before it was finally completed in 1836. When it was done, it had none of the memorials to Napoleon's personal glory that he had intended.

Trump, who has also spent a great deal of his second term enthusiastically "redecorating" the surviving parts of the White House with gold-colored appliqués and signs labeling the Oval Office, has been carrying around actual models of his planned arch for months now.

Why does this matter?

• Quite literally nobody other than Donald Trump ever thought this was necessary or a good use of resources.