I am looking for an idiom/expression which implies defeating the opponent in a debate / an argument / a discussion and making one's own word / opinion the one that counts.
I know the idiom "have the last word on something (e.g. an argument)", but it sounds a bit off to me here! whereas it is more about a word that decisively or conclusively ends a discussion; i.e. to me it means: "to say the last word" rather than succeeding to make one's word/opinion the one that counts in an argument!
Example: Amy and Jake can argue with each other for hours because each of them insists on having the last word. Source
A) Why do you keep trying to justify your mistakes?
B) Come on! That's not true!
A) But whenever we discuss you try to ......................!
(Needed connotation: he always wants to make his own opinion / demand / word the one that both parties agree with. Even though the opponent does not tend to accept it.)
I was wondering what is the most appropriate idiom in this sense to be used to fill in the blank above?
P.S. I am not quite sure whether I am correct or mistaken about my take on the expression "have the last word"! Please kindly help me with it and let me know if there is any better choice here especially in AE.