That is where you are wrong.
In your own mind you don’t need one.
And Trump can’t just do it by “fiat,” either.
Not saying he would or wants to, but he can’t even if he wanted to by fiat.
No.
In your own mind, you don't understand the 14th amendment.
It's been covered enough here over the years.
Obama rewrote our Constitution and Congressional laws by fiat and the GOPe and judicial system did nothing to stop him.
Why wouldn’t Trump do the same?