Did Trump have the power to fire Mueller, Rosenstein, etc. directly?

Or is a middle-man officially required?

According to this he couldn’t fire Mueller, but he could have fired Rosenstein:

But he didn’t do that. He went to McGahn. Why? If he wanted Mueller gone, why didn’t he go to Rosenstein? AFAIK, McGahn didn’t have the power to do what Trump wanted.

Trump, in business and in government, has been surprisingly chicken-shit about firing people. (Not on his TV show, obvs.) He gets others to do it for him. Some cites:

https://www.washingtonpost.com/outlook/2018/.../president-trump-is-afraid-fire-people/

Yeah, but McGahn couldn’t fire Mueller or Rosenstein for that matter, so I don’t see what he had to say to McGahn means much. Rosenstein didn’t report to McGahn. He might as well have told Barron to talk to Rosenstein.

It seems like he’s separated by at least one turn before Rosenstein is fired and 2 before Mueller is. If that turn isn’t exhausted he’s just bloviating.

I suspect he thought he could use McGahn like he used all his Trump Org lackeys: as messengers from the king. McGahn could deliver the bad news.

EDIT:

But he doesn’t talk to Barron very much.

I suspect that as well. But it’s not like McGahn was the only person on the planet that could talk to Rosenstein. People that wouldn’t resign either. And even if McGahn had done it, I suspect he would have been rebuffed by Rosenstein. Then what does he do, send McGahn back to say “Rosenstein, you’re fired!”? McGahn can’t do that.

I think on this particular point was one and possibly more steps removed from actual obstruction.

Why couldn’t McGahn do that if the president had decided it? Having the power to decide if someone is fired doesn’t equal an obligation to be the person who tells them.

John Kelly didn’t have the power to fire the Secretary of State, but he was still the one who told Tillerson he was out.

And Trump doesn’t know or care what he can or cannot do or who is the right person to go through. When he tells an underling to make something happen, they are supposed to make that something happen.