Answer:
The election determined whether or not Eckels remained rich in the future.
Explanation:
In the first instance where the election is mentioned, Eckels states very delightedly gives thanks God that Keith won the race for the seat of the President Of The United States. Eckels states that if Keith had lost, he would have been trying to get away from the consequences of the same.
In the next instance, Eckels back from a time travel trip realizes that Keith lost the election and puts the gun to this head and "click".
According to the story, he a very rich businessman had taken to time travel as a hobby, going off into the past to shoot game.
There were certain rules that guided this endeavor. One of them was that he must not kill that he wasn't allowed or permitted to kill. Anything considered as a major disturbance to the past would affect events in the future.
Eckels somehow kills a butterfly and that results in the shift in the results of the elections by the time he gets back to the present.
Cheers