The US Constitution grants Congress, not the executive branch, the power to determine how the federal government’s money is spent.
Elon Musk’s team within the Executive Office of the President have reportedly gained full admin access to the payment system of the Bureau of the Fiscal Service at the Department of the Treasury, which is responsible for the majority of the federal government’s payments, and are using that access to prevent certain payments from being made. Among other things, they are also attempting to close down the US Agency for International Development, which was established and funded as an independent agency by an act of Congress.
With regards to the constitution specifically the power of the purse seems a little vague. In 1974 the Impoundment Control Act was passed as a response to, and to prevent, presidents from unilaterally impounding.
https://protectdemocracy.org/work/impoundment-threat-explain...
This is a very interesting way of saying "following the law."
And no, being elected to a public office is no blank cheque to dismantle checks on that office by other branches of government.
Does that mean that the real coup happened when Trump picked the supreme court justices? Perhaps, but again it was very legal, and not particularly out of step from previous norms.
If you compare that to germany in the 1930s, a common example of a self-coup, you'll see some similarities but also large differences...
> The Reichstag building... caught fire... Hitler immediately accused the Communists of being the perpetrators... Using this justification, Hitler persuaded Hindenburg to enact the Reichstag Fire Decree. The decree abolished most civil liberties, including the right to speak, assemble, protest, and due process... the Nazis declared a state of emergency and began a violent crackdown against their political enemies... Hitler submitted a proposal to the Reichstag that if passed would immediately grant all legislative powers to the cabinet... allow Hitler's government to act without regard to the constitution.
https://en.wikipedia.org/wiki/Enabling_Act_of_1933 (Edited for brevity)
I would encourage you to learn more about that day. Most people that were charged did not go into the building. And the few that did were literally waved in by police, including many being escorted around inside by police.