And for the very same reason President Trump can tell Mueller and his little gang of flying monkeys to kiss his ass since they are creatures of Congress. The same could be said for all of those insane Federal Judges trying to dictate the Executive Branch on immigration and defense because Federal Courts are also creations of Congress. The only thing that can truly touch a president is impeachment or the 25th amendment, that's it.
The President can be fired by Congress. The President cannot do anything like that back to Congress in return.
Hmmm..... I thought that the special counsel was appointed by the Department of Justice, not the Congress.