"Constitutional crisis" for firing FBI?

[Little-Acorn]

https://www.voanews.com/a/mark-warner-says-trump-firing-mueller-could-provoke-constitutional-crisis/4172416.html
"Constitutional crisis" for firing FBI?
how can there be a "constitutional crisis" for firing FBI, when the founders didn't create the FBI, and the Constitution never called for the forming of an FBI?

And when no FBI (or Mueller) have been fired?

Nobody has even talked about firing anyone in the FBI, or Mueller, except the leftist media who were desperate for a subject they could bash Trump for. So they invented "Will Trump fire Mueller???" out of thin air, with no evidence Trump had ever wanted to fire Mueller. And then they proceeded to discuss it, publish headlines about it, question each other over the air about it, and generally carry on as if Trump were actually thinking about it.

Trump never had to lift a finger. Didn't have to fire anybody, didn't even have to consider it. Suddenly he was guilty in the court of public opinion anyway, guilty of firing Mueller when he never even contemplated it.