Where in the story "Hunters in the Snow" does the plot clearly illuminate the struggle for power among the three principal characters?
Although the term "struggle for power" is possibly too forceful for this story, the relationship of the three characters is based almost entirely on their perceived roles. Kenny is the leader, and feels that insulting Tub is justified. Frank is the second-banana, and goes along with Kenny, but shifts his allegience to Tub when Tub shows a more aggressive nature. Tub doesn't care about power, but wants to be accepted; when he gains the role of leader, he (possibly subconsciously) realizes that he can now take revenge on Kenny.
The driver... looked like a cartoon of a person laughing, except that his eyes watched the man on the seat beside him. "You ought to see yourself," the driver said. "He looks just like a beach ball with a hat on, doesn't he? Doesn't he, Frank?"
The man beside him smiled and looked off.
"You almost ran me down," Tub said. "You could've killed me."
(Wolff, "Hunters in the Snow," classicshorts.com)
Earlier in the story, Kenny drives at Tub to scare him, but then subtly looks to Frank for approval, showing his own insecurity in his role. It is clear that although Kenny and Tub fill the role of "leader" at different times, they both need Frank to approve of them, giving them validation in their actions. Without a "yes-man," they believe the power of leadership cannot be validated, and so Frank's role is almost more important than either Tub's or Kenny's.