The Republican commentator machine is already going full bore against Mueller, so it's not as if Trump will face any repercussions from Hill Republicans for firing him.
Although Trump can't personally fire him, he would direct Rosenstein to fire Mueller. If Rosenstein refused, then Trump would fire him and the new acting DAG would fire Mueller - and if he didn't, Trump would fire him then go move through the ranks until he had an acting DAG that would fire Mueller. By which point, Senate Republicans have to explain why a DAG they unanimously voted to confirm just a couple months and a special counsel they've praised up and down deserved to be fired so suddenly.
Comey's firing led to Mueller's appointment as special counsel, so "not at all" seems like a strange read on this, unless your inclination is to believe in the worst of everything!