[ROCKLOBSTER]

I don’t know why impeachment cannot be used to remove people under the president when the president fails to remove them from office for not doing their job.

Well, I know you can impeach judges, and we should have been for a while.

[shalom aleichem]

Those subject to impeachment are listed in Article II, Section 4: “The President, Vice President and all civil officers of the United States, shall be removed from office on impeachment for, and conviction of, treason, bribery, or other high crimes and misdemeanors.”

“All civil officers” clearly includes the errant and contumacious Attorney General and any other underling whom Congress wishes to expel.

There is some dispute whether a member of Congress is included, although it has been done before.
http://en.wikipedia.org/wiki/Impeachment#Officials_subject_to_impeachment