kingmaker
/ˈkɪŋmeɪkər/Definitions
1. noun
A person or group that has significant influence or power to determine the choice of a leader or ruler, often in a position of authority or influence.
“The kingmaker behind the scenes had a significant role in deciding the next leader of the country.”
2. verb
To have a significant influence or power in determining the choice of a leader or ruler.
“The politician was said to have kingmaked the next president of the United States.”