From an article posted on Yahoo news, the power to tax and the power to spend by government. Has been split between the executive branch (The old Kings in England) and Parliament, such as our Congress, This traces back to the original MAGNA CARTA, that was also a basis of our USA Constitution.

Trump recently, is trying to override the spending that was directed by Congress in the budgets and laws they have created. This essentially is taking that power of spending out of the Control of Congress. Which is unconstitutional, and some of the other actions might be illegal. While Trump may claim the recent immunity from criminal acts a recent Supreme Court seemed to have awarded him. The people working for him, may not share that immunity. Such as Elon Musk

Time will tell, but read this article on how this has developed over centuries in England and then later to the forefathers when they drafted the constitution.
Here is an excerpt from that article below in "" Quotes. A link to the article is farther below that.

"The two indispensable powers of legislatures in all Anglo-American constitutional systems are the complementary powers to tax the people and to authorize expenditure by the executive. The rule that kings could not levy taxes without legislative consent has its origins in the Magna Carta of 1215 and was made definite by 1300. But over time, Parliament became equally insistent that the king could not spend the revenue raised by Parliament however he pleased. In the five centuries that preceded the American Revolution, parliamentary control of the national purse was the primary weapon in preventing royal absolutism."

IF YOU CARE ABOUT THIS , CALL YOUR REPRESENTATIVES IN CONGRESS AND THE HOUSE, there is a page for the Nebraska and Iowa representatives on this website.

The link to the article is here

https://www.yahoo.com/news/donald-trump-claiming-powers-king-185129235.html